feat: Neutrale Rechnungsvorlage als Kundenstandard

backend/src/main/frontend/invoice-generator/profile-invoice-generator.js

@@ -7,9 +7,40 @@ window.profileInvoiceState = window.profileInvoiceState || {
   initialized: false
 };
 
-window.initProfileInvoiceGenerator = function() {
+// A tab can still be hidden when Vaadin sends its selected-change response.
+// Wait for its actual layout instead of relying on fixed delays and a server callback.
+window.showProfileInvoiceTemplate = function(container, view, templateData, masterdata, vatRate) {
+  if (window.pendingProfileInvoiceLoad) {
+    window.pendingProfileInvoiceLoad.disconnect();
+    window.pendingProfileInvoiceLoad = null;
+  }
+  function loadWhenVisible() {
+    var rect = container.getBoundingClientRect();
+    if (rect.width <= 0 || rect.height <= 0) return false;
+    window.invoiceGeneratorViewProfile = view;
+    window.profileInvoiceServiceData = null;
+    window.profileInvoiceVatRate = vatRate;
+    window.masterdataValues = masterdata;
+    window.initProfileInvoiceGenerator(container);
+    window.loadProfileTemplate(templateData);
+    return true;
+  }
+  if (!loadWhenVisible()) {
+    var observer = new ResizeObserver(function() {
+      if (window.pendingProfileInvoiceLoad !== observer) return;
+      if (loadWhenVisible()) {
+        observer.disconnect();
+        if (window.pendingProfileInvoiceLoad === observer) window.pendingProfileInvoiceLoad = null;
+      }
+    });
+    window.pendingProfileInvoiceLoad = observer;
+    observer.observe(container);
+  }
+};
+
+window.initProfileInvoiceGenerator = function(container) {
   var containerId = 'invoice-canvas-container-profile';
-  var container = document.getElementById(containerId);
+  container = container || document.getElementById(containerId);
   
   if (!container) {
     console.error('Canvas container not found:', containerId);
@@ -1303,7 +1334,7 @@ window.initProfileInvoiceGenerator = function() {
             } else if (el.variable.startsWith('masterdata.')) {
               // Masterdata variables - use actual value from masterdata or placeholder
               var value = masterdata[el.variable];
-              if (value && value.trim() !== '') {
+              if (typeof value === 'string') {
                 el.text = value;
               } else {
                 el.text = '[' + el.variable.replace('masterdata.', '') + ']';

backend/src/main/java/de/assecutor/votianlt/pages/view/CreateInvoiceView.java

@@ -33,6 +33,7 @@ import de.assecutor.votianlt.repository.ServiceRepository;
 import de.assecutor.votianlt.repository.UserRepository;
 import de.assecutor.votianlt.security.SecurityService;
 import de.assecutor.votianlt.service.CustomerInvoiceService;
+import de.assecutor.votianlt.service.CustomerInvoiceTemplateVariables;
 import de.assecutor.votianlt.service.EmailService;
 import de.assecutor.votianlt.service.InvoiceLifecycleException;
 import de.assecutor.votianlt.service.InvoiceLifecycleService;
@@ -546,15 +547,9 @@ public class CreateInvoiceView extends VerticalLayout implements HasUrlParameter
 
             currentUser = currentUserOpt.get();
 
-            Optional<InvoiceTemplate> templateOpt = invoiceTemplateService
+            InvoiceTemplate template = invoiceTemplateService
-                    .getTemplateByUserId(currentUser.getId().toString());
+                    .getCustomerTemplateByUserId(currentUser.getId().toString());
-            if (templateOpt.isEmpty()) {
+            String templateData = template.getTemplateData();
-                Notification.show(getTranslation("createinvoice.notification.notemplate"), 3000,
-                        Notification.Position.BOTTOM_END);
-                return;
-            }
-
-            String templateData = templateOpt.get().getTemplateData();
             if (templateData == null || templateData.isBlank()) {
                 Notification.show(getTranslation("createinvoice.notification.notemplate"), 3000,
                         Notification.Position.BOTTOM_END);
@@ -822,15 +817,8 @@ public class CreateInvoiceView extends VerticalLayout implements HasUrlParameter
         BigDecimal totalAmount = netAmount.add(vatAmount);
 
         // Build variable substitution map
-        Map<String, String> variables = new HashMap<>();
+        Map<String, String> variables = CustomerInvoiceTemplateVariables.create(currentUser,
-
+                userInvoiceDataService.findByUserId(currentUser.getId()).orElse(null), invoiceNumber);
-        // Master data (from user profile)
-        variables.put("masterdata.company_name", safe(currentUser.getCompany()));
-        variables.put("masterdata.contact_name", safe(currentUser.getFirstname()) + " " + safe(currentUser.getName()));
-        variables.put("masterdata.street", safe(currentUser.getStreet()) + " " + safe(currentUser.getHouseNumber()));
-        variables.put("masterdata.city", safe(currentUser.getZip()) + " " + safe(currentUser.getCity()));
-        variables.put("masterdata.email", safe(currentUser.getEmail()));
-        variables.put("masterdata.phone", safe(currentUser.getPhone()));
 
         // Customer data (from job - look up Customer entity for full address)
         String customerSelection = currentJob.getCustomerSelection();

backend/src/main/java/de/assecutor/votianlt/pages/view/EditProfileView.java

@@ -44,6 +44,7 @@ import de.assecutor.votianlt.pages.service.UserInvoiceDataService;
 import de.assecutor.votianlt.repository.ServiceRepository;
 import de.assecutor.votianlt.security.SecurityService;
 import de.assecutor.votianlt.service.CustomerInvoiceService;
+import de.assecutor.votianlt.service.CustomerInvoiceTemplateVariables;
 import de.assecutor.votianlt.service.InvoiceTemplateService;
 import de.assecutor.votianlt.service.LanguageService;
 import com.vaadin.flow.component.grid.Grid;
@@ -78,6 +79,7 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
     private Checkbox billingEnabled;
     private NumberField vatRateField;
     private VerticalLayout propertiesPanelProfile;
+    private final Div canvasContainer;
 
     private final ServiceRepository serviceRepository;
     private Grid<Service> servicesGrid;
@@ -414,7 +416,7 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
                 .set("border-radius", "var(--lumo-border-radius-m)").set("padding", "var(--lumo-space-m)");
 
         // Mitte: Canvas
-        Div canvasContainer = new Div();
+        canvasContainer = new Div();
         canvasContainer.setId("invoice-canvas-container-profile");
         canvasContainer.setWidth("100%");
         canvasContainer.setHeight("100%");
@@ -513,17 +515,10 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
         // Bestehende Rechnungsdaten laden (nur für die Checkbox)
         loadInvoiceData();
 
-        // Initialize invoice generator when the billing tab is selected
+        // Load directly; the client waits until the billing canvas is visible.
-        // Also register this view instance for JavaScript callbacks
         tabSheet.addSelectedChangeListener(e -> {
             if (getTranslation("profile.invoicecreation").equals(e.getSelectedTab().getLabel())) {
-                getElement().executeJs("window.invoiceGeneratorViewProfile = $0;"
+                loadInvoiceTemplate();
-                        + "window.profileInvoiceServiceData = null;" + "setTimeout(function() { "
-                        + "  if (window.initProfileInvoiceGenerator) { " + "    window.initProfileInvoiceGenerator(); "
-                        + "    console.log('Canvas initialized, now loading template...'); "
-                        + "    setTimeout(function() { " + "      $0.$server.onCanvasReady(); " + "    }, 200); "
-                        + "  } else { " + "    console.error('initProfileInvoiceGenerator not found'); " + "  } "
-                        + "}, 300);", getElement());
             }
         });
 
@@ -858,6 +853,16 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
         currentInvoiceData = userInvoiceDataService.createOrUpdate(currentUser.getId(), billingEnabled.getValue(),
                 prefixField.getValue(), ustIdField.getValue(), taxNumberField.getValue(), bankNameField.getValue(),
                 ibanField.getValue(), "19", introTextArea.getValue(), termsTextArea.getValue());
+        try {
+            String valuesJson = new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(
+                    CustomerInvoiceTemplateVariables.create(currentUser, currentInvoiceData,
+                            prefixField.getValue() + "12345"));
+            getElement().executeJs("if (window.updateProfileMasterdataValue) { "
+                    + "Object.entries(JSON.parse($0)).forEach(([key, value]) => "
+                    + "window.updateProfileMasterdataValue(key, value)); }", valuesJson);
+        } catch (com.fasterxml.jackson.core.JsonProcessingException ex) {
+            throw new IllegalStateException("Could not update invoice template values", ex);
+        }
     }
 
     private String safe(String value) {
@@ -957,7 +962,7 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
                             }
                             BigDecimal previewVatRate = getPreviewVatRate();
                             byte[] pdfBytes = customerInvoiceService.generatePdfFromCanvasTemplate(templateData,
-                                    currentUser, prefixField.getValue(), previewVatRate);
+                                    currentUser, prefixField.getValue(), previewVatRate, currentInvoiceData);
                             showPdfInDialog(pdfBytes);
                         } catch (Exception ex) {
                             Notification.show(getTranslation("profile.invoice.pdf.preview.error", ex.getMessage()),
@@ -1479,62 +1484,23 @@ public class EditProfileView extends HorizontalLayout implements HasDynamicTitle
         }));
     }
 
-    /**
-     * Called by JavaScript when the canvas is ready
-     */
-    @ClientCallable
-    public void onCanvasReady() {
-        System.out.println("Canvas ready, loading template...");
-        loadInvoiceTemplate();
-    }
-
     /**
      * Load the saved invoice template from database and display it on the canvas
      */
     private void loadInvoiceTemplate() {
         try {
-            java.util.Optional<de.assecutor.votianlt.model.InvoiceTemplate> optionalTemplate = invoiceTemplateService
+            String templateData = invoiceTemplateService.getCustomerTemplateByUserId(currentUser.getId().toString())
-                    .getTemplateByUserId(currentUser.getId().toString());
+                    .getTemplateData();
-            if (optionalTemplate.isPresent()) {
+            if (templateData == null || templateData.isBlank()) {
-                String templateData = optionalTemplate.get().getTemplateData();
+                return;
-                if (templateData != null && !templateData.isEmpty()) {
+            }
-                    System.out.println("Loading template data: "
-                            + templateData.substring(0, Math.min(100, templateData.length())) + "...");
-                    // Escape the JSON string for JavaScript
-                    String escapedJson = templateData.replace("\\", "\\\\").replace("'", "\\'").replace("\n", "\\n")
-                            .replace("\r", "\\r");
-                    // Build masterdata values JSON
-                    String company = safe(currentUser.getCompany());
-                    String fullName = safe(currentUser.getFirstname()) + " " + safe(currentUser.getName());
-                    String street = safe(currentUser.getStreet()) + " " + safe(currentUser.getHouseNumber());
-                    String city = safe(currentUser.getZip()) + " " + safe(currentUser.getCity());
-                    String email = safe(currentUser.getEmail());
-                    String phone = safe(currentUser.getPhone());
             String prefix = prefixField.getValue();
             String invoiceNumber = (prefix != null && !prefix.isBlank() ? prefix : "") + "12345";
-                    String masterdataJson = "{" + "'masterdata.company_name': '" + company.replace("'", "\\'") + "',"
+            String masterdataJson = new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(
-                            + "'masterdata.contact_name': '" + fullName.replace("'", "\\'") + "',"
+                    CustomerInvoiceTemplateVariables.create(currentUser, currentInvoiceData, invoiceNumber));
-                            + "'masterdata.street': '" + street.replace("'", "\\'") + "'," + "'masterdata.city': '"
+            getElement().executeJs("window.showProfileInvoiceTemplate($0, $1, JSON.parse($2), JSON.parse($3), $4);",
-                            + city.replace("'", "\\'") + "'," + "'masterdata.email': '" + email.replace("'", "\\'")
+                    canvasContainer.getElement(), getElement(), templateData, masterdataJson,
-                            + "'," + "'masterdata.phone': '" + phone.replace("'", "\\'") + "',"
+                    getPreviewVatRate().doubleValue());
-                            + "'masterdata.invoice_number': '" + invoiceNumber.replace("'", "\\'") + "'" + "}";
-                    BigDecimal rate = currentUser.getVatRate() != null ? currentUser.getVatRate()
-                            : Service.FIXED_VAT_RATE;
-                    double vatRateJs = rate.doubleValue();
-                    getElement().executeJs("setTimeout(function() { "
-                            + "  if (window.loadProfileTemplate && document.getElementById('invoice-canvas-container-profile')) { "
-                            + "    console.log('Loading template into canvas...'); "
-                            + "    window.profileInvoiceServiceData = null; "
-                            + "    window.profileInvoiceVatRate = " + vatRateJs + "; "
-                            + "    window.masterdataValues = "
-                            + masterdataJson + "; " + "    var templateData = JSON.parse('" + escapedJson + "'); "
-                            + "    window.loadProfileTemplate(templateData); " + "  } else { "
-                            + "    console.error('loadProfileTemplate or canvas not available'); " + "  } "
-                            + "}, 300);");
-                }
-            } else {
-                System.out.println("No template found for user: " + currentUser.getId());
-            }
         } catch (Exception ex) {
             System.err.println("Fehler beim Laden des Templates: " + ex.getMessage());
             ex.printStackTrace();

backend/src/main/java/de/assecutor/votianlt/service/CustomerInvoiceService.java

@@ -263,6 +263,12 @@ public class CustomerInvoiceService {
 
     public byte[] generatePdfFromCanvasTemplate(String jsonTemplateData, de.assecutor.votianlt.model.User user,
             String invoicePrefix, BigDecimal vatRate) throws Exception {
+        return generatePdfFromCanvasTemplate(jsonTemplateData, user, invoicePrefix, vatRate, null);
+    }
+
+    public byte[] generatePdfFromCanvasTemplate(String jsonTemplateData, de.assecutor.votianlt.model.User user,
+            String invoicePrefix, BigDecimal vatRate, de.assecutor.votianlt.model.UserInvoiceData billing)
+            throws Exception {
         BigDecimal effectiveVatRate = vatRate != null ? vatRate
                 : (user != null && user.getVatRate() != null ? user.getVatRate() : new BigDecimal("0.19"));
 
@@ -270,16 +276,8 @@ public class CustomerInvoiceService {
         java.util.Map<String, String> variables = new java.util.HashMap<>();
 
         if (user != null) {
-            // Use actual user data
+            variables.putAll(CustomerInvoiceTemplateVariables.create(user, billing,
-            String company = user.getCompany();
+                    (invoicePrefix != null && !invoicePrefix.isBlank() ? invoicePrefix : "") + "12345"));
-            variables.put("masterdata.company_name", (company != null && !company.isEmpty()) ? company : "Ihre Firma");
-            variables.put("masterdata.contact_name", safe(user.getFirstname()) + " " + safe(user.getName()));
-            variables.put("masterdata.street", safe(user.getStreet()) + " " + safe(user.getHouseNumber()));
-            variables.put("masterdata.city", safe(user.getZip()) + " " + safe(user.getCity()));
-            variables.put("masterdata.email", safe(user.getEmail()));
-            variables.put("masterdata.phone", safe(user.getPhone()));
-            variables.put("masterdata.invoice_number",
-                    (invoicePrefix != null && !invoicePrefix.isBlank() ? invoicePrefix : "") + "12345");
         } else {
             // Default values for preview without user
             variables.put("masterdata.company_name", "Meine Firma GmbH");
@@ -575,6 +573,14 @@ public class CustomerInvoiceService {
                 .append(String.format(java.util.Locale.GERMANY, "%,.2f €", netTotal)).append("</td>");
         html.append("</tr>");
 
+        html.append("<tr>");
+        html.append("<td style='width:55%;padding:2px 0;'></td>");
+        html.append("<td style='width:20%;text-align:left;padding:2px 8px;white-space:nowrap;'>zzgl. ")
+                .append(vatLabel).append(" USt:</td>");
+        html.append("<td style='width:25%;text-align:right;padding:2px 8px;white-space:nowrap;font-weight:bold;'>")
+                .append(String.format(java.util.Locale.GERMANY, "%,.2f €", netTotal * vatRate.doubleValue()))
+                .append("</td></tr>");
+
         // Gesamtsumme - label in col 2, value in col 3
         html.append("<tr>");
         html.append("<td style='width:55%;padding:2px 0;'></td>");

backend/src/main/java/de/assecutor/votianlt/service/CustomerInvoiceTemplateVariables.java

@@ -0,0 +1,61 @@
+package de.assecutor.votianlt.service;
+
+import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.model.UserInvoiceData;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/** Shared issuer values for the customer editor, PDF preview and actual invoice. */
+public final class CustomerInvoiceTemplateVariables {
+    private CustomerInvoiceTemplateVariables() {
+    }
+
+    public static Map<String, String> create(User user, UserInvoiceData billing, String invoiceNumber) {
+        Map<String, String> values = new LinkedHashMap<>();
+        String contact = join(" ", user.getFirstname(), user.getName());
+        String company = safe(user.getCompany());
+        if (company.isEmpty()) {
+            company = contact;
+        }
+        String street = join(" ", user.getStreet(), user.getHouseNumber());
+        String city = join(" ", user.getZip(), user.getCity());
+        values.put("masterdata.company_name", company);
+        values.put("masterdata.contact_name", contact);
+        values.put("masterdata.street", street);
+        values.put("masterdata.city", city);
+        values.put("masterdata.email", safe(user.getEmail()));
+        values.put("masterdata.phone", safe(user.getPhone()));
+        values.put("masterdata.sender_line", join(" · ", company, street, city));
+        values.put("masterdata.contact_details", join("\n", user.getEmail(), user.getPhone()));
+        values.put("masterdata.invoice_number", safe(invoiceNumber));
+        values.put("masterdata.invoice_date", LocalDate.now().format(DateTimeFormatter.ofPattern("dd.MM.yyyy")));
+        values.put("masterdata.tax_details", billing == null ? ""
+                : join("\n", labeled("USt-IdNr.: ", billing.getUstId()),
+                        labeled("Steuernummer: ", billing.getTaxNumber())));
+        values.put("masterdata.bank_details", billing == null ? ""
+                : join("\n", billing.getBankName(), labeled("IBAN: ", billing.getIban())));
+        String intro = billing == null ? "" : safe(billing.getIntroText());
+        values.put("masterdata.intro", intro.isEmpty() ? "Wir berechnen Ihnen folgende Leistungen:" : intro);
+        String terms = billing == null ? "" : safe(billing.getPaymentTerms());
+        values.put("masterdata.payment_terms", terms.isEmpty()
+                ? "Bitte geben Sie bei der Zahlung die Rechnungsnummer an." : terms);
+        return values;
+    }
+
+    private static String labeled(String label, String value) {
+        return safe(value).isEmpty() ? "" : label + safe(value);
+    }
+
+    private static String join(String separator, String... parts) {
+        return Stream.of(parts).map(CustomerInvoiceTemplateVariables::safe).filter(s -> !s.isEmpty())
+                .collect(Collectors.joining(separator));
+    }
+
+    private static String safe(String value) {
+        return value == null ? "" : value.strip();
+    }
+}

backend/src/main/java/de/assecutor/votianlt/service/DemoModeService.java

@@ -1,12 +1,10 @@
 package de.assecutor.votianlt.service;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import de.assecutor.votianlt.model.AppUser;
 import de.assecutor.votianlt.model.Barcode;
 import de.assecutor.votianlt.model.Comment;
 import de.assecutor.votianlt.model.Customer;
 import de.assecutor.votianlt.model.DeliveryStation;
-import de.assecutor.votianlt.model.InvoiceTemplate;
 import de.assecutor.votianlt.model.Job;
 import de.assecutor.votianlt.model.JobServiceSelection;
 import de.assecutor.votianlt.model.JobStatus;
@@ -37,9 +35,7 @@ import de.assecutor.votianlt.repository.TaskTemplateRepository;
 import de.assecutor.votianlt.repository.UserInvoiceDataRepository;
 import de.assecutor.votianlt.repository.UserRepository;
 import de.assecutor.votianlt.security.SessionAuthenticationService;
-import java.io.IOException;
 import java.math.BigDecimal;
-import java.nio.charset.StandardCharsets;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
@@ -54,7 +50,6 @@ import java.util.Set;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.bson.types.ObjectId;
-import org.springframework.core.io.ClassPathResource;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -68,7 +63,6 @@ public class DemoModeService {
     public static final String DEMO_PASSWORD = "demo";
     private static final String DEMO_FIRST_NAME = "Demo";
     private static final String DEMO_LAST_NAME = "Benutzer";
-    private static final String DEMO_INVOICE_TEMPLATE_RESOURCE = "templates/demo_invoice_template_default.json";
 
     private final DemoSessionRegistry demoSessionRegistry;
     private final SessionAuthenticationService sessionAuthenticationService;
@@ -194,7 +188,6 @@ public class DemoModeService {
         List<Service> services = seedDemoServices(demoUser);
         List<Customer> customers = seedDemoCustomers(demoUser);
         seedDemoJobs(demoUser, customers, services);
-        seedDemoInvoiceTemplate(demoUser);
     }
 
     private void cleanupDemoAppUserData(List<AppUser> demoAppUsers) {
@@ -441,23 +434,6 @@ public class DemoModeService {
         return selection;
     }
 
-    private void seedDemoInvoiceTemplate(User demoUser) {
-        InvoiceTemplate template = new InvoiceTemplate(demoUser.getId().toHexString(), "Einfach",
-                createDemoInvoiceTemplateData());
-        invoiceTemplateRepository.save(template);
-    }
-
-    private String createDemoInvoiceTemplateData() {
-        try {
-            String templateJson = new String(
-                    new ClassPathResource(DEMO_INVOICE_TEMPLATE_RESOURCE).getInputStream().readAllBytes(),
-                    StandardCharsets.UTF_8);
-            return new ObjectMapper().writeValueAsString(templateJson);
-        } catch (IOException ex) {
-            throw new IllegalStateException("Could not load demo invoice template", ex);
-        }
-    }
-
     private void applyCustomerToPickup(Job job, Customer customer) {
         if (job == null || customer == null) {
             return;

backend/src/main/java/de/assecutor/votianlt/service/InvoiceTemplateService.java

@@ -1,16 +1,23 @@
 package de.assecutor.votianlt.service;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.JsonNode;
 import de.assecutor.votianlt.model.InvoiceTemplate;
 import de.assecutor.votianlt.repository.InvoiceTemplateRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
+import org.springframework.core.io.ClassPathResource;
 
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.Optional;
 
 @Service
 @RequiredArgsConstructor
 public class InvoiceTemplateService {
 
+    public static final String CUSTOMER_DEFAULT_USER_ID = "CUSTOMER_DEFAULT";
+
     private final InvoiceTemplateRepository invoiceTemplateRepository;
 
     /**
@@ -36,6 +43,49 @@ public class InvoiceTemplateService {
         return invoiceTemplateRepository.findByUserId(userId);
     }
 
+    /**
+     * Customer invoices use the neutral default if no usable personal template is
+     * stored. Reading the default never creates or overwrites a database record.
+     */
+    public InvoiceTemplate getCustomerTemplateByUserId(String userId) {
+        if (userId == null || userId.isBlank() || "SYSTEM".equals(userId) || CUSTOMER_DEFAULT_USER_ID.equals(userId)) {
+            throw new IllegalArgumentException("A customer user ID is required");
+        }
+        return invoiceTemplateRepository.findByUserId(userId)
+                .filter(template -> hasTemplateElements(template.getTemplateData()))
+                .orElseGet(() -> invoiceTemplateRepository.findByUserId(CUSTOMER_DEFAULT_USER_ID)
+                        .filter(template -> hasTemplateElements(template.getTemplateData()))
+                        // Saving the customer's edits must never change the shared default.
+                        .map(template -> new InvoiceTemplate(userId, template.getName(), template.getTemplateData()))
+                        .orElseGet(() -> loadBundledCustomerDefault(userId)));
+    }
+
+    private InvoiceTemplate loadBundledCustomerDefault(String userId) {
+        try (var input = new ClassPathResource("templates/customer_invoice_template_neutral.json").getInputStream()) {
+            String json = new String(input.readAllBytes(), StandardCharsets.UTF_8);
+            return new InvoiceTemplate(userId, "Neutral", new ObjectMapper().writeValueAsString(json));
+        } catch (IOException ex) {
+            throw new IllegalStateException("Could not load neutral customer invoice template", ex);
+        }
+    }
+
+    private boolean hasTemplateElements(String templateData) {
+        if (templateData == null || templateData.isBlank()) {
+            return false;
+        }
+        try {
+            ObjectMapper mapper = new ObjectMapper();
+            JsonNode data = mapper.readTree(templateData);
+            // Templates can be stored as an object or as a JSON-encoded string.
+            if (data != null && data.isTextual()) {
+                data = mapper.readTree(data.textValue());
+            }
+            return data != null && data.path("elements").isArray() && !data.path("elements").isEmpty();
+        } catch (IOException ex) {
+            return false;
+        }
+    }
+
     /**
      * Check if a template exists for a user
      */

backend/src/main/resources/templates/customer_invoice_template_neutral.json

@@ -0,0 +1,420 @@
+{
+  "elements": [
+    {
+      "id": "neutral-company",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "5.70071",
+      "widthPercent": "61.51261",
+      "heightPercent": "3.56295",
+      "fontSize": 20,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.company_name"
+    },
+    {
+      "id": "neutral-document-label",
+      "type": "text",
+      "text": "RECHNUNG",
+      "xPercent": "71.93277",
+      "yPercent": "6.88836",
+      "widthPercent": "19.32773",
+      "heightPercent": "2.13777",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "textAlign": "right",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-street",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "10.80760",
+      "widthPercent": "57.14286",
+      "heightPercent": "1.66271",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.street"
+    },
+    {
+      "id": "neutral-city",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "12.58907",
+      "widthPercent": "57.14286",
+      "heightPercent": "1.66271",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.city"
+    },
+    {
+      "id": "neutral-header-rule",
+      "type": "line",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "16.50831",
+      "widthPercent": "82.52101",
+      "heightPercent": "0.11876",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-sender",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "20.30879",
+      "widthPercent": "82.52101",
+      "heightPercent": "1.18765",
+      "fontSize": 7,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.sender_line"
+    },
+    {
+      "id": "neutral-recipient-company_name",
+      "type": "text",
+      "text": "Kundenfirma GmbH",
+      "xPercent": "8.73950",
+      "yPercent": "23.27791",
+      "widthPercent": "47.89916",
+      "heightPercent": "1.78147",
+      "fontSize": 11,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": true,
+      "variable": "customer.company_name"
+    },
+    {
+      "id": "neutral-recipient-contact_name",
+      "type": "text",
+      "text": "Erika Mustermann",
+      "xPercent": "8.73950",
+      "yPercent": "25.05938",
+      "widthPercent": "47.89916",
+      "heightPercent": "1.78147",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": true,
+      "variable": "customer.contact_name"
+    },
+    {
+      "id": "neutral-recipient-street",
+      "type": "text",
+      "text": "Kundenstraße 456",
+      "xPercent": "8.73950",
+      "yPercent": "26.84086",
+      "widthPercent": "47.89916",
+      "heightPercent": "1.78147",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": true,
+      "variable": "customer.street"
+    },
+    {
+      "id": "neutral-recipient-city",
+      "type": "text",
+      "text": "54321 Kundenstadt",
+      "xPercent": "8.73950",
+      "yPercent": "28.62233",
+      "widthPercent": "47.89916",
+      "heightPercent": "1.78147",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": true,
+      "variable": "customer.city"
+    },
+    {
+      "id": "neutral-number-label",
+      "type": "text",
+      "text": "RECHNUNGSNUMMER",
+      "xPercent": "63.52941",
+      "yPercent": "23.15914",
+      "widthPercent": "27.73109",
+      "heightPercent": "1.42518",
+      "fontSize": 8,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-number",
+      "type": "text",
+      "text": "",
+      "xPercent": "63.52941",
+      "yPercent": "25.05938",
+      "widthPercent": "27.73109",
+      "heightPercent": "1.90024",
+      "fontSize": 11,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.invoice_number"
+    },
+    {
+      "id": "neutral-date-label",
+      "type": "text",
+      "text": "RECHNUNGSDATUM",
+      "xPercent": "63.52941",
+      "yPercent": "28.38480",
+      "widthPercent": "27.73109",
+      "heightPercent": "1.42518",
+      "fontSize": 8,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-date",
+      "type": "text",
+      "text": "",
+      "xPercent": "63.52941",
+      "yPercent": "30.28504",
+      "widthPercent": "27.73109",
+      "heightPercent": "1.90024",
+      "fontSize": 11,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.invoice_date"
+    },
+    {
+      "id": "neutral-services-heading",
+      "type": "text",
+      "text": "Leistungen",
+      "xPercent": "8.73950",
+      "yPercent": "36.34204",
+      "widthPercent": "82.52101",
+      "heightPercent": "2.37530",
+      "fontSize": 14,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-intro",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "39.90499",
+      "widthPercent": "82.52101",
+      "heightPercent": "3.56295",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.intro"
+    },
+    {
+      "id": "neutral-services",
+      "type": "text",
+      "text": "Rechnungspositionen",
+      "xPercent": "8.73950",
+      "yPercent": "45.24941",
+      "widthPercent": "82.52101",
+      "heightPercent": "27.67221",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "services.list"
+    },
+    {
+      "id": "neutral-payment-label",
+      "type": "text",
+      "text": "ZAHLUNG",
+      "xPercent": "8.73950",
+      "yPercent": "78.02850",
+      "widthPercent": "82.52101",
+      "heightPercent": "1.42518",
+      "fontSize": 8,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-payment",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "80.40380",
+      "widthPercent": "82.52101",
+      "heightPercent": "4.98812",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.payment_terms"
+    },
+    {
+      "id": "neutral-footer-rule",
+      "type": "line",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "88.83610",
+      "widthPercent": "82.52101",
+      "heightPercent": "0.11876",
+      "fontSize": 10,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#202020",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-contact-label",
+      "type": "text",
+      "text": "KONTAKT",
+      "xPercent": "8.73950",
+      "yPercent": "90.61758",
+      "widthPercent": "26.21849",
+      "heightPercent": "1.30641",
+      "fontSize": 8,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-contact",
+      "type": "text",
+      "text": "",
+      "xPercent": "8.73950",
+      "yPercent": "92.87411",
+      "widthPercent": "26.21849",
+      "heightPercent": "3.32542",
+      "fontSize": 8,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#444444",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.contact_details"
+    },
+    {
+      "id": "neutral-tax-label",
+      "type": "text",
+      "text": "STEUERANGABEN",
+      "xPercent": "38.65546",
+      "yPercent": "90.61758",
+      "widthPercent": "25.37815",
+      "heightPercent": "1.30641",
+      "fontSize": 8,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-tax",
+      "type": "text",
+      "text": "",
+      "xPercent": "38.65546",
+      "yPercent": "92.87411",
+      "widthPercent": "25.37815",
+      "heightPercent": "3.32542",
+      "fontSize": 8,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#444444",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.tax_details"
+    },
+    {
+      "id": "neutral-bank-label",
+      "type": "text",
+      "text": "BANKVERBINDUNG",
+      "xPercent": "67.22689",
+      "yPercent": "90.61758",
+      "widthPercent": "24.03361",
+      "heightPercent": "1.30641",
+      "fontSize": 8,
+      "fontStyle": "bold",
+      "textAlign": "left",
+      "color": "#555555",
+      "isStatic": false,
+      "isCustomer": false,
+      "variable": null
+    },
+    {
+      "id": "neutral-bank",
+      "type": "text",
+      "text": "",
+      "xPercent": "67.22689",
+      "yPercent": "92.87411",
+      "widthPercent": "24.03361",
+      "heightPercent": "3.32542",
+      "fontSize": 8,
+      "fontStyle": "normal",
+      "textAlign": "left",
+      "color": "#444444",
+      "isStatic": true,
+      "isCustomer": false,
+      "variable": "masterdata.bank_details"
+    }
+  ]
+}

backend/src/main/resources/templates/demo_invoice_template_default.json

@@ -1,187 +0,0 @@
-{
-  "elements": [
-    {
-      "id": "demo-title",
-      "type": "header",
-      "text": "Rechnung",
-      "xPercent": "7.56",
-      "yPercent": "6.53",
-      "widthPercent": "28.07",
-      "heightPercent": "4.04",
-      "fontSize": 24,
-      "fontStyle": "bold",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-number-label",
-      "type": "text",
-      "text": "Rechnungsnr.",
-      "xPercent": "67.06",
-      "yPercent": "7.48",
-      "widthPercent": "17.98",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "bold",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-number-value",
-      "type": "text",
-      "text": "000000",
-      "xPercent": "84.03",
-      "yPercent": "7.48",
-      "widthPercent": "10.08",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "normal",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "invoice.number"
-    },
-    {
-      "id": "demo-date-label",
-      "type": "text",
-      "text": "Datum",
-      "xPercent": "67.06",
-      "yPercent": "11.52",
-      "widthPercent": "17.98",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "bold",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-date-value",
-      "type": "text",
-      "text": "2026-01-01",
-      "xPercent": "84.03",
-      "yPercent": "11.52",
-      "widthPercent": "10.08",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "normal",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "invoice.date"
-    },
-    {
-      "id": "demo-sender",
-      "type": "text",
-      "text": null,
-      "xPercent": "7.56",
-      "yPercent": "16.51",
-      "widthPercent": "30.08",
-      "heightPercent": "2.97",
-      "fontSize": 12,
-      "fontStyle": "bold",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "masterdata.contact_name"
-    },
-    {
-      "id": "demo-customer",
-      "type": "customer",
-      "text": "Kundenname\nStraße Nr.\nPLZ Ort",
-      "xPercent": "7.56",
-      "yPercent": "25.06",
-      "widthPercent": "33.95",
-      "heightPercent": "12.00",
-      "fontSize": 12,
-      "fontStyle": "normal",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-services",
-      "type": "text",
-      "text": "Leistungen",
-      "xPercent": "7.56",
-      "yPercent": "42.04",
-      "widthPercent": "85.04",
-      "heightPercent": "28.03",
-      "fontSize": 11,
-      "fontStyle": "normal",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "services.list"
-    },
-    {
-      "id": "demo-net-label",
-      "type": "text",
-      "text": "Netto",
-      "xPercent": "67.06",
-      "yPercent": "73.99",
-      "widthPercent": "11.93",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "bold",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-net-value",
-      "type": "text",
-      "text": "0,00 €",
-      "xPercent": "80.00",
-      "yPercent": "73.99",
-      "widthPercent": "13.95",
-      "heightPercent": "2.97",
-      "fontSize": 11,
-      "fontStyle": "normal",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "invoice.net_total"
-    },
-    {
-      "id": "demo-total-label",
-      "type": "text",
-      "text": "Gesamt",
-      "xPercent": "67.06",
-      "yPercent": "78.98",
-      "widthPercent": "11.93",
-      "heightPercent": "3.44",
-      "fontSize": 13,
-      "fontStyle": "bold",
-      "color": "#111111"
-    },
-    {
-      "id": "demo-total-value",
-      "type": "text",
-      "text": "0,00 €",
-      "xPercent": "80.00",
-      "yPercent": "78.98",
-      "widthPercent": "13.95",
-      "heightPercent": "3.44",
-      "fontSize": 13,
-      "fontStyle": "bold",
-      "color": "#111111",
-      "isStatic": true,
-      "variable": "invoice.gross_total"
-    },
-    {
-      "id": "demo-template-note",
-      "type": "text",
-      "text": "Hinweis: Dieses Rechnungstemplate kann vom Benutzer ",
-      "xPercent": "0.00",
-      "yPercent": "20.78",
-      "widthPercent": "100.00",
-      "heightPercent": "4.51",
-      "fontSize": 20,
-      "fontStyle": "normal",
-      "textAlign": "center",
-      "color": "#555555"
-    },
-    {
-      "id": "element-1",
-      "type": "text",
-      "text": "frei angepasst werden.",
-      "xPercent": "31.93",
-      "yPercent": "24.94",
-      "widthPercent": "25.21",
-      "heightPercent": "3.56",
-      "fontSize": 20,
-      "color": "#333333",
-      "isStatic": false,
-      "isCustomer": false,
-      "variable": null
-    }
-  ]
-}

backend/src/test/frontend/profile-invoice-generator.test.js

@@ -21,6 +21,12 @@ function createEditor() {
     addEventListener() {}
   };
   const window = { addEventListener() {} };
+  const resizeObservers = [];
+  class ResizeObserver {
+    constructor(callback) { this.callback = callback; resizeObservers.push(this); }
+    observe() {}
+    disconnect() { this.disconnected = true; }
+  }
   class Image {
     width = 595;
     height = 842;
@@ -30,6 +36,7 @@ function createEditor() {
     window,
     document: { getElementById: () => container, createElement: () => canvas },
     Image,
+    ResizeObserver,
     console: { log() {}, error(error) { throw new Error(String(error)); } }
   });
   window.initProfileInvoiceGenerator();
@@ -37,7 +44,7 @@ function createEditor() {
     { id: 'letterhead', type: 'image', imageData: 'data:image/svg+xml;base64,test', x: 0, y: 0, width: 595, height: 842 },
     { id: 'invoice-text', type: 'text', text: 'Rechnung', x: 50, y: 250, width: 100, height: 30 }
   ] });
-  return { window, painted, pendingImages };
+  return { window, painted, pendingImages, container, resizeObservers };
 }
 
 test('invoice text stays above a letterhead that finishes loading later', () => {
@@ -58,3 +65,55 @@ test('a removed letterhead is not painted when its pending image finishes loadin
   pendingImages[0].onload();
   assert.deepEqual(painted, [['text', 'Rechnung']]);
 });
+
+test('optional billing data stays empty while unknown variables retain a placeholder', () => {
+  const { window } = createEditor();
+  window.masterdataValues = { 'masterdata.bank_details': '' };
+  window.loadProfileTemplate({ elements: [
+    { id: 'bank', type: 'text', variable: 'masterdata.bank_details', text: 'Old bank', x: 0, y: 0 },
+    { id: 'unknown', type: 'text', variable: 'masterdata.unknown', x: 0, y: 20 }
+  ] });
+  assert.equal(window.profileInvoiceState.elements[0].text, '');
+  assert.equal(window.profileInvoiceState.elements[1].text, '[unknown]');
+});
+
+const neutralTemplate = JSON.parse(readFileSync(new URL('../../main/resources/templates/customer_invoice_template_neutral.json', import.meta.url), 'utf8'));
+
+test('the neutral profile template loads when its initially hidden tab becomes visible', () => {
+  const { window, container, resizeObservers } = createEditor();
+  container.getBoundingClientRect = () => ({ width: 0, height: 0 });
+  window.showProfileInvoiceTemplate(container, {}, JSON.stringify(neutralTemplate), { 'masterdata.company_name': 'Kundenfirma' }, 0.19);
+  assert.equal(resizeObservers.length, 1);
+  assert.equal(window.profileInvoiceState.elements[0].id, 'letterhead');
+
+  container.getBoundingClientRect = () => ({ width: 615, height: 862 });
+  resizeObservers[0].callback();
+
+  assert.equal(window.profileInvoiceState.elements.length, neutralTemplate.elements.length);
+  assert.equal(window.profileInvoiceState.elements[0].id, 'neutral-company');
+  assert.equal(window.profileInvoiceState.elements[0].text, 'Kundenfirma');
+  assert.equal(resizeObservers[0].disconnected, true);
+  assert.equal(window.pendingProfileInvoiceLoad, null);
+});
+
+test('opening another customer profile cancels a pending template load', () => {
+  const { window, container, resizeObservers } = createEditor();
+  container.getBoundingClientRect = () => ({ width: 0, height: 0 });
+  window.showProfileInvoiceTemplate(container, {}, neutralTemplate, { 'masterdata.company_name': 'Vorheriger Kunde' }, 0.19);
+  window.showProfileInvoiceTemplate(container, {}, neutralTemplate, { 'masterdata.company_name': 'Aktueller Kunde' }, 0.07);
+  assert.equal(resizeObservers[0].disconnected, true);
+
+  container.getBoundingClientRect = () => ({ width: 615, height: 862 });
+  resizeObservers[0].callback();
+  assert.equal(window.profileInvoiceState.elements[0].id, 'letterhead');
+  resizeObservers[1].callback();
+  assert.equal(window.profileInvoiceState.elements[0].text, 'Aktueller Kunde');
+  assert.equal(window.profileInvoiceVatRate, 0.07);
+});
+
+test('a visible profile canvas loads the template immediately', () => {
+  const { window, container, resizeObservers } = createEditor();
+  window.showProfileInvoiceTemplate(container, {}, neutralTemplate, { 'masterdata.company_name': 'Kundenfirma' }, 0.19);
+  assert.equal(resizeObservers.length, 0);
+  assert.equal(window.profileInvoiceState.elements[0].id, 'neutral-company');
+});

backend/src/test/java/de/assecutor/votianlt/service/CustomerInvoiceTemplateRenderingTest.java

@@ -0,0 +1,73 @@
+package de.assecutor.votianlt.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfReader;
+import com.itextpdf.kernel.pdf.canvas.parser.PdfTextExtractor;
+import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.model.UserInvoiceData;
+import java.io.ByteArrayInputStream;
+import java.math.BigDecimal;
+import java.nio.charset.StandardCharsets;
+import org.junit.jupiter.api.Test;
+import org.springframework.core.io.ClassPathResource;
+
+class CustomerInvoiceTemplateRenderingTest {
+    @Test
+    void neutralTemplateResolvesProfilePreviewAndActualInvoiceData() throws Exception {
+        String template;
+        try (var stream = new ClassPathResource("templates/customer_invoice_template_neutral.json").getInputStream()) {
+            template = new String(stream.readAllBytes(), StandardCharsets.UTF_8);
+        }
+        User user = new User();
+        user.setCompany("Logistik & Partner");
+        user.setStreet("Hafenstraße");
+        user.setHouseNumber("12");
+        user.setZip("20457");
+        user.setCity("Hamburg");
+        user.setEmail("rechnung@example.com");
+        UserInvoiceData billing = new UserInvoiceData();
+        billing.setTaxNumber("12/345/67890");
+        billing.setBankName("Musterbank");
+        billing.setIban("DE89 3704 0044 0532 0130 00");
+        var service = new CustomerInvoiceService();
+
+        String preview = extractText(service.generatePdfFromCanvasTemplate(template, user, "RE-",
+                new BigDecimal("0.19"), billing));
+
+        assertThat(preview).contains("Logistik & Partner", "RE-12345", "Kundenfirma GmbH", "124,45 €", "779,45 €",
+                "Steuernummer: 12/345/67890", "IBAN: DE89 3704 0044 0532 0130 00");
+        var values = CustomerInvoiceTemplateVariables.create(user, billing, "RE-2026-001");
+        values.put("customer.company_name", "Kunde & Co.");
+        values.put("customer.contact_name", "Erika Muster");
+        values.put("customer.street", "Kundenstraße 1");
+        values.put("customer.city", "10115 Berlin");
+        values.put("services.json", "[{\"name\":\"Transport\",\"netAmount\":\"100,00\"}]");
+        values.put("invoice.net_total", "100,00 €");
+        values.put("invoice.vat_total", "19,00 €");
+        values.put("invoice.gross_total", "119,00 €");
+        values.put("invoice.vat_rate", "19%");
+        ObjectMapper mapper = new ObjectMapper();
+        for (var element : mapper.readTree(template).path("elements")) {
+            String variable = element.path("variable").asText("");
+            if (!variable.isBlank() && !"services.list".equals(variable)) {
+                assertThat(values).containsKey(variable);
+            }
+        }
+        String invoice = extractText(service.generatePdfFromCanvasTemplateWithData(
+                mapper.writeValueAsString(template), values, user));
+
+        assertThat(invoice).contains("Logistik & Partner", "Kunde & Co.", "Erika Muster", "RE-2026-001",
+                "Transport", "119,00 €", "Musterbank", "Steuernummer: 12/345/67890")
+                .doesNotContain("Kundenfirma GmbH", "Assecutor", "[invoice_date]", "[bank_details]", "null");
+    }
+
+    private String extractText(byte[] pdfBytes) throws Exception {
+        try (var pdf = new PdfDocument(new PdfReader(new ByteArrayInputStream(pdfBytes)))) {
+            assertThat(pdf.getNumberOfPages()).isEqualTo(1);
+            return PdfTextExtractor.getTextFromPage(pdf.getPage(1));
+        }
+    }
+}

backend/src/test/java/de/assecutor/votianlt/service/CustomerInvoiceTemplateVariablesTest.java

@@ -0,0 +1,56 @@
+package de.assecutor.votianlt.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import de.assecutor.votianlt.model.User;
+import de.assecutor.votianlt.model.UserInvoiceData;
+import org.junit.jupiter.api.Test;
+
+class CustomerInvoiceTemplateVariablesTest {
+    @Test
+    void usesCustomerProfileAndBillingDataIncludingMultilineText() {
+        User user = new User();
+        user.setCompany("Müller & Söhne");
+        user.setStreet("Hafenstraße");
+        user.setHouseNumber("12");
+        user.setZip("20457");
+        user.setCity("Hamburg");
+        user.setEmail("rechnung@example.com");
+        user.setPhone("040 12345");
+        UserInvoiceData billing = new UserInvoiceData();
+        billing.setUstId("DE123456789");
+        billing.setTaxNumber("12/345/67890");
+        billing.setBankName("Musterbank");
+        billing.setIban("DE89 3704 0044 0532 0130 00");
+        billing.setIntroText("Vielen Dank für Ihren Auftrag.\nWir berechnen folgende Leistungen:");
+        billing.setPaymentTerms("Bitte binnen 14 Tagen zahlen.");
+
+        var values = CustomerInvoiceTemplateVariables.create(user, billing, "RE-2026-0001");
+
+        assertThat(values).containsEntry("masterdata.company_name", "Müller & Söhne")
+                .containsEntry("masterdata.sender_line", "Müller & Söhne · Hafenstraße 12 · 20457 Hamburg")
+                .containsEntry("masterdata.contact_details", "rechnung@example.com\n040 12345")
+                .containsEntry("masterdata.tax_details", "USt-IdNr.: DE123456789\nSteuernummer: 12/345/67890")
+                .containsEntry("masterdata.bank_details", "Musterbank\nIBAN: DE89 3704 0044 0532 0130 00")
+                .containsEntry("masterdata.intro", billing.getIntroText())
+                .containsEntry("masterdata.payment_terms", billing.getPaymentTerms())
+                .containsEntry("masterdata.invoice_number", "RE-2026-0001");
+        assertThat(values.get("masterdata.invoice_date")).matches("\\d{2}\\.\\d{2}\\.\\d{4}");
+    }
+
+    @Test
+    void absentBillingDataDoesNotInventTaxOrBankDetails() {
+        User user = new User();
+        user.setFirstname("Erika");
+        user.setName("Beispiel");
+
+        var values = CustomerInvoiceTemplateVariables.create(user, null, "RE-1");
+
+        assertThat(values).containsEntry("masterdata.company_name", "Erika Beispiel")
+                .containsEntry("masterdata.tax_details", "").containsEntry("masterdata.bank_details", "")
+                .containsEntry("masterdata.contact_details", "")
+                .containsEntry("masterdata.intro", "Wir berechnen Ihnen folgende Leistungen:")
+                .containsEntry("masterdata.payment_terms", "Bitte geben Sie bei der Zahlung die Rechnungsnummer an.");
+        assertThat(values.values()).noneMatch(value -> value.contains("null") || value.contains("Assecutor"));
+    }
+}

backend/src/test/java/de/assecutor/votianlt/service/DemoModeServiceTest.java

@@ -2,6 +2,7 @@ package de.assecutor.votianlt.service;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.anyList;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
@@ -10,7 +11,6 @@ import static org.mockito.Mockito.when;
 import de.assecutor.votianlt.model.Job;
 import de.assecutor.votianlt.model.JobStatus;
 import de.assecutor.votianlt.model.User;
-import de.assecutor.votianlt.model.InvoiceTemplate;
 import de.assecutor.votianlt.pages.domain.CustomerRepository;
 import de.assecutor.votianlt.repository.AppUserRepository;
 import de.assecutor.votianlt.repository.BarcodeRepository;
@@ -90,8 +90,6 @@ class DemoModeServiceTest {
     private ArgumentCaptor<List<Job>> jobsCaptor;
     @Captor
     private ArgumentCaptor<List<de.assecutor.votianlt.model.Service>> servicesCaptor;
-    @Captor
-    private ArgumentCaptor<InvoiceTemplate> invoiceTemplateCaptor;
 
     private DemoSessionRegistry demoSessionRegistry;
     private DemoModeService demoModeService;
@@ -127,17 +125,8 @@ class DemoModeServiceTest {
         assertThat(prepared).isTrue();
         verify(serviceRepository).saveAll(servicesCaptor.capture());
         assertThat(servicesCaptor.getValue()).hasSize(2);
-        verify(invoiceTemplateRepository).save(invoiceTemplateCaptor.capture());
+        // Demo customers use the same neutral default as all other customers.
-        assertThat(invoiceTemplateCaptor.getValue().getUserId()).isEqualTo(demoUser.getId().toHexString());
+        verify(invoiceTemplateRepository, never()).save(any());
-        assertThat(invoiceTemplateCaptor.getValue().getTemplateData())
-                .contains("elements")
-                .contains("services.list")
-                .contains("invoice.gross_total")
-                .contains("frei angepasst werden")
-                .contains("textAlign")
-                .contains("center")
-                .contains("fontSize")
-                .contains("20");
         verify(jobRepository).saveAll(jobsCaptor.capture());
         assertThat(jobsCaptor.getValue()).hasSize(2);
         assertThat(jobsCaptor.getValue()).extracting(Job::getJobNumber)

backend/src/test/java/de/assecutor/votianlt/service/InvoiceTemplateServiceTest.java

@@ -0,0 +1,139 @@
+package de.assecutor.votianlt.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import de.assecutor.votianlt.model.InvoiceTemplate;
+import de.assecutor.votianlt.repository.InvoiceTemplateRepository;
+import java.util.Optional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.NullAndEmptySource;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class InvoiceTemplateServiceTest {
+    @Mock
+    private InvoiceTemplateRepository repository;
+    private InvoiceTemplateService service;
+
+    @BeforeEach
+    void setUp() {
+        service = new InvoiceTemplateService(repository);
+    }
+
+    @Test
+    void missingCustomerTemplateUsesEditableDefaultWithoutWritingToDatabase() throws Exception {
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.empty());
+
+        InvoiceTemplate result = service.getCustomerTemplateByUserId("customer-1");
+
+        assertThat(result.getUserId()).isEqualTo("customer-1");
+        assertThat(result.getName()).isEqualTo("Neutral");
+        assertThat(result.getId()).isNull();
+        ObjectMapper mapper = new ObjectMapper();
+        var template = mapper.readTree(mapper.readValue(result.getTemplateData(), String.class));
+        assertThat(template.path("elements").size()).isGreaterThan(10);
+        assertThat(template.toString()).contains("masterdata.company_name", "customer.company_name", "services.list",
+                "masterdata.bank_details", "masterdata.tax_details").doesNotContain("Assecutor", "HHA", "DE6720");
+        verify(repository).findByUserId("customer-1");
+        verify(repository).findByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID);
+        verifyNoMoreInteractions(repository);
+    }
+
+    @Test
+    void personalTemplateTakesPrecedence() {
+        InvoiceTemplate personal = new InvoiceTemplate("customer-1", "Mein Briefpapier",
+                "{\"elements\":[{\"type\":\"text\",\"text\":\"Eigene Vorlage\"}]}");
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.of(personal));
+
+        assertThat(service.getCustomerTemplateByUserId("customer-1")).isSameAs(personal);
+        verify(repository).findByUserId("customer-1");
+        verifyNoMoreInteractions(repository);
+    }
+
+    @ParameterizedTest
+    @NullAndEmptySource
+    @ValueSource(strings = { " ", "null", "{}", "{\"elements\":[]}", "\"{\\\"elements\\\":[]}\"", "invalid JSON" })
+    void unusableSavedTemplateFallsBackWithoutOverwritingIt(String data) {
+        InvoiceTemplate existing = new InvoiceTemplate("customer-1", "Standard", data);
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.of(existing));
+
+        InvoiceTemplate result = service.getCustomerTemplateByUserId("customer-1");
+
+        assertThat(result.getTemplateData()).contains("neutral-company", "services.list");
+        assertThat(existing.getTemplateData()).isEqualTo(data);
+        verify(repository).findByUserId("customer-1");
+        verify(repository).findByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID);
+        verifyNoMoreInteractions(repository);
+    }
+
+    @Test
+    void jsonEncodedPersonalTemplateTakesPrecedence() throws Exception {
+        InvoiceTemplate personal = new InvoiceTemplate("customer-1", "Standard", new ObjectMapper()
+                .writeValueAsString("{\"elements\":[{\"type\":\"text\",\"text\":\"Eigene Vorlage\"}]}"));
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.of(personal));
+
+        assertThat(service.getCustomerTemplateByUserId("customer-1")).isSameAs(personal);
+    }
+
+    @Test
+    void systemTemplateDoesNotFallBackToCustomerDefault() {
+        when(repository.findByUserId("SYSTEM")).thenReturn(Optional.empty());
+
+        assertThat(service.getTemplateByUserId("SYSTEM")).isEmpty();
+        assertThatThrownBy(() -> service.getCustomerTemplateByUserId("SYSTEM"))
+                .isInstanceOf(IllegalArgumentException.class);
+        assertThatThrownBy(() -> service.getCustomerTemplateByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID))
+                .isInstanceOf(IllegalArgumentException.class);
+    }
+
+    @Test
+    void sharedDefaultIsLoadedAsAnUnsavedCustomerTemplate() {
+        InvoiceTemplate shared = new InvoiceTemplate(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID, "Neutral",
+                "{\"elements\":[{\"type\":\"text\",\"text\":\"Gemeinsamer Standard\"}]}");
+        shared.setId("shared-template-id");
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.empty());
+        when(repository.findByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID)).thenReturn(Optional.of(shared));
+
+        InvoiceTemplate result = service.getCustomerTemplateByUserId("customer-1");
+
+        assertThat(result.getUserId()).isEqualTo("customer-1");
+        assertThat(result.getId()).isNull();
+        assertThat(result.getTemplateData()).isEqualTo(shared.getTemplateData());
+        assertThat(shared.getUserId()).isEqualTo(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID);
+        verify(repository).findByUserId("customer-1");
+        verify(repository).findByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID);
+        verifyNoMoreInteractions(repository);
+    }
+
+    @Test
+    void invalidSharedDefaultUsesBundledNeutralTemplate() {
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.empty());
+        when(repository.findByUserId(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID))
+                .thenReturn(Optional.of(new InvoiceTemplate(InvoiceTemplateService.CUSTOMER_DEFAULT_USER_ID, "Neutral", "{}")));
+
+        assertThat(service.getCustomerTemplateByUserId("customer-1").getTemplateData()).contains("neutral-company");
+    }
+
+    @Test
+    void defaultCanBeSavedAsPersonalTemplate() {
+        when(repository.findByUserId("customer-1")).thenReturn(Optional.empty());
+        String templateData = service.getCustomerTemplateByUserId("customer-1").getTemplateData();
+        var saved = org.mockito.ArgumentCaptor.forClass(InvoiceTemplate.class);
+
+        service.saveTemplate("customer-1", templateData);
+
+        verify(repository).save(saved.capture());
+        assertThat(saved.getValue().getUserId()).isEqualTo("customer-1");
+        assertThat(saved.getValue().getTemplateData()).isEqualTo(templateData);
+    }
+}