diff --git a/backend/prisma/migrations/20260813100000_bank_card_number/migration.sql b/backend/prisma/migrations/20260813100000_bank_card_number/migration.sql
new file mode 100644
index 00000000..8a5992dc
--- /dev/null
+++ b/backend/prisma/migrations/20260813100000_bank_card_number/migration.sql
@@ -0,0 +1,2 @@
+-- Kartennummer (Debit-/Kontokarte) als optionales Feld an der Bankkarte.
+ALTER TABLE `BankCard` ADD COLUMN IF NOT EXISTS `cardNumber` VARCHAR(191) NULL;
diff --git a/backend/prisma/schema.prisma b/backend/prisma/schema.prisma
index fedd3b88..c3400dee 100644
--- a/backend/prisma/schema.prisma
+++ b/backend/prisma/schema.prisma
@@ -353,6 +353,7 @@ model BankCard {
   customer      Customer   @relation(fields: [customerId], references: [id], onDelete: Cascade)
   accountHolder String
   iban          String
+  cardNumber    String?    // Karten-/Kontokartennummer (optional, z.B. Debitkarte)
   bic           String?
   bankName      String?
   expiryDate    DateTime?
diff --git a/backend/src/controllers/customer.controller.ts b/backend/src/controllers/customer.controller.ts
index 54029af1..059cf6fb 100644
--- a/backend/src/controllers/customer.controller.ts
+++ b/backend/src/controllers/customer.controller.ts
@@ -433,7 +433,7 @@ export async function updateBankCard(req: AuthRequest, res: Response): Promise<v
     if (before) {
       const changes: Record<string, { von: unknown; nach: unknown }> = {};
       const fieldLabels: Record<string, string> = {
-        iban: 'IBAN', bic: 'BIC', bankName: 'Bank',
+        iban: 'IBAN', bic: 'BIC', bankName: 'Bank', cardNumber: 'Kartennummer',
         accountHolder: 'Kontoinhaber', isActive: 'Aktiv',
       };
       for (const [key, newVal] of Object.entries(data)) {
diff --git a/backend/src/services/customer.service.ts b/backend/src/services/customer.service.ts
index 64fdc3d7..f694cc7b 100644
--- a/backend/src/services/customer.service.ts
+++ b/backend/src/services/customer.service.ts
@@ -302,6 +302,7 @@ export async function createBankCard(
   data: {
     accountHolder: string;
     iban: string;
+    cardNumber?: string;
     bic?: string;
     bankName?: string;
     expiryDate?: Date;
@@ -322,6 +323,7 @@ export async function updateBankCard(
   data: {
     accountHolder?: string;
     iban?: string;
+    cardNumber?: string;
     bic?: string;
     bankName?: string;
     expiryDate?: Date;
diff --git a/docs/todo.md b/docs/todo.md
index 6ec004c1..59441d5b 100644
--- a/docs/todo.md
+++ b/docs/todo.md
@@ -97,6 +97,22 @@ isolierte Instanz (keine Multi-Tenancy im Code), Provisioning + Abrechnung
 
 ## ✅ Erledigt
 
+- [x] **🪪 Bankkarte-/Ausweis-Details in Vertrag (Ansicht + Bearbeiten) + Kartennummer** (2026-08-13)
+  - **Schema:** neues Feld `BankCard.cardNumber` (String?, optional). Migration
+    `20260813100000_bank_card_number` (`ADD COLUMN IF NOT EXISTS`), auf Dev
+    angewandt + `prisma generate`. Prod zieht via `migrate deploy` im Entrypoint.
+    Eingabefeld „Kartennummer" im Bankkarten-Modal (Kundenakte) ergänzt.
+  - **Vertragsansicht (ContractDetail)** – Karten „Bankkarte"/„Ausweis" zeigen
+    zusätzlich (jeweils mit Copy-Button, nur wenn gesetzt):
+    - Bankkarte: BIC, Bank, Kartennummer, Ablaufdatum
+    - Ausweis: Behörde, Ausstellung, Ablaufdatum + **Geburtsort/Geburtsdatum
+      vom Kunden**
+  - **Vertrag bearbeiten (ContractForm)** – unter den Bankkarte-/Ausweis-
+    Dropdowns dieselben Detailfelder der aktuell gewählten Karte/Ausweis
+    (Copy-Buttons). Selects dafür je in eigenem `<div>` gewrappt (Grid-Alignment).
+  - Datenquelle war bereits vorhanden: `getContractById` (bankCard/identityDocument/
+    customer) + `getCustomerById` (bankCards/identityDocuments) liefern alle Felder.
+
 - [x] **📄 PDF-Viewer-Modal für Bankkarte-/Ausweis-Dokument** (2026-08-13)
   - Neue wiederverwendbare Komponente `PdfViewerModal` (Modal + `<iframe>` auf
     `viewUrl(documentPath)`, inkl. „In neuem Tab" + „Herunterladen"). Nutzt den
diff --git a/frontend/src/pages/contracts/ContractDetail.tsx b/frontend/src/pages/contracts/ContractDetail.tsx
index 0a74823d..57976fc6 100644
--- a/frontend/src/pages/contracts/ContractDetail.tsx
+++ b/frontend/src/pages/contracts/ContractDetail.tsx
@@ -2681,7 +2681,30 @@ export default function ContractDetail() {
               {c.bankCard.iban}
               <CopyButton value={c.bankCard.iban} />
             </p>
-            {c.bankCard.bankName && <p className="text-gray-500">{c.bankCard.bankName}</p>}
+            {c.bankCard.bic && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">BIC:</span> {c.bankCard.bic}
+                <CopyButton value={c.bankCard.bic} />
+              </p>
+            )}
+            {c.bankCard.bankName && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Bank:</span> {c.bankCard.bankName}
+                <CopyButton value={c.bankCard.bankName} />
+              </p>
+            )}
+            {c.bankCard.cardNumber && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Kartennummer:</span> {c.bankCard.cardNumber}
+                <CopyButton value={c.bankCard.cardNumber} />
+              </p>
+            )}
+            {c.bankCard.expiryDate && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Ablaufdatum:</span> {formatDate(c.bankCard.expiryDate)}
+                <CopyButton value={formatDate(c.bankCard.expiryDate)} />
+              </p>
+            )}
             {c.bankCard.description && (
               <p className="text-sm text-gray-600 mt-1 italic whitespace-pre-line">
                 {c.bankCard.description}
@@ -2709,6 +2732,36 @@ export default function ContractDetail() {
               <CopyButton value={c.identityDocument.documentNumber} />
             </p>
             <p className="text-gray-500">{c.identityDocument.type}</p>
+            {c.identityDocument.issuingAuthority && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Behörde:</span> {c.identityDocument.issuingAuthority}
+                <CopyButton value={c.identityDocument.issuingAuthority} />
+              </p>
+            )}
+            {c.identityDocument.issueDate && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Ausstellung:</span> {formatDate(c.identityDocument.issueDate)}
+                <CopyButton value={formatDate(c.identityDocument.issueDate)} />
+              </p>
+            )}
+            {c.identityDocument.expiryDate && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Ablaufdatum:</span> {formatDate(c.identityDocument.expiryDate)}
+                <CopyButton value={formatDate(c.identityDocument.expiryDate)} />
+              </p>
+            )}
+            {c.customer?.birthPlace && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Geburtsort:</span> {c.customer.birthPlace}
+                <CopyButton value={c.customer.birthPlace} />
+              </p>
+            )}
+            {c.customer?.birthDate && (
+              <p className="text-sm text-gray-600 flex items-center gap-1">
+                <span className="text-gray-500">Geburtsdatum:</span> {formatDate(c.customer.birthDate)}
+                <CopyButton value={formatDate(c.customer.birthDate)} />
+              </p>
+            )}
           </Card>
         )}
       </div>
diff --git a/frontend/src/pages/contracts/ContractForm.tsx b/frontend/src/pages/contracts/ContractForm.tsx
index c99660c3..8265acda 100644
--- a/frontend/src/pages/contracts/ContractForm.tsx
+++ b/frontend/src/pages/contracts/ContractForm.tsx
@@ -1041,6 +1041,7 @@ export default function ContractForm() {
               />
             </div>
             <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
+              <div>
               <Select
                 label={
                   <span className="inline-flex items-center gap-1">
@@ -1077,7 +1078,25 @@ export default function ContractForm() {
                   };
                 })}
               />
+              {selectedBankCard && (
+                <div className="mt-1.5 space-y-0.5 text-xs text-gray-600">
+                  {selectedBankCard.bic && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">BIC:</span> {selectedBankCard.bic}<CopyButton value={selectedBankCard.bic} /></div>
+                  )}
+                  {selectedBankCard.bankName && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Bank:</span> {selectedBankCard.bankName}<CopyButton value={selectedBankCard.bankName} /></div>
+                  )}
+                  {selectedBankCard.cardNumber && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Kartennummer:</span> {selectedBankCard.cardNumber}<CopyButton value={selectedBankCard.cardNumber} /></div>
+                  )}
+                  {selectedBankCard.expiryDate && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Ablaufdatum:</span> {formatDate(selectedBankCard.expiryDate)}<CopyButton value={formatDate(selectedBankCard.expiryDate)} /></div>
+                  )}
+                </div>
+              )}
+              </div>
 
+              <div>
               <Select
                 label={
                   <span className="inline-flex items-center gap-1">
@@ -1106,6 +1125,26 @@ export default function ContractForm() {
                   label: `${d.documentNumber} (${d.type})`,
                 }))}
               />
+              {selectedDocument && (
+                <div className="mt-1.5 space-y-0.5 text-xs text-gray-600">
+                  {selectedDocument.issueDate && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Ausstellung:</span> {formatDate(selectedDocument.issueDate)}<CopyButton value={formatDate(selectedDocument.issueDate)} /></div>
+                  )}
+                  {selectedDocument.expiryDate && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Ablaufdatum:</span> {formatDate(selectedDocument.expiryDate)}<CopyButton value={formatDate(selectedDocument.expiryDate)} /></div>
+                  )}
+                  {selectedDocument.issuingAuthority && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Behörde:</span> {selectedDocument.issuingAuthority}<CopyButton value={selectedDocument.issuingAuthority} /></div>
+                  )}
+                  {customer?.birthPlace && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Geburtsort:</span> {customer.birthPlace}<CopyButton value={customer.birthPlace} /></div>
+                  )}
+                  {customer?.birthDate && (
+                    <div className="flex items-center gap-1"><span className="text-gray-500">Geburtsdatum:</span> {formatDate(customer.birthDate)}<CopyButton value={formatDate(customer.birthDate)} /></div>
+                  )}
+                </div>
+              )}
+              </div>
             </div>
           </Card>
         )}
diff --git a/frontend/src/pages/customers/CustomerDetail.tsx b/frontend/src/pages/customers/CustomerDetail.tsx
index 2b6287fa..96e149c2 100644
--- a/frontend/src/pages/customers/CustomerDetail.tsx
+++ b/frontend/src/pages/customers/CustomerDetail.tsx
@@ -2697,6 +2697,7 @@ function BankCardModal({
   const getInitialFormData = () => ({
     accountHolder: bankCard?.accountHolder || '',
     iban: bankCard?.iban || '',
+    cardNumber: bankCard?.cardNumber || '',
     bic: bankCard?.bic || '',
     bankName: bankCard?.bankName || '',
     expiryDate: bankCard?.expiryDate ? new Date(bankCard.expiryDate).toISOString().split('T')[0] : '',
@@ -2753,7 +2754,7 @@ function BankCardModal({
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['customer', customerId] });
       onClose();
-      setFormData({ accountHolder: '', iban: '', bic: '', bankName: '', expiryDate: '', description: '', isActive: true });
+      setFormData({ accountHolder: '', iban: '', cardNumber: '', bic: '', bankName: '', expiryDate: '', description: '', isActive: true });
     },
   });
 
@@ -2830,6 +2831,12 @@ function BankCardModal({
           </div>
         </div>
 
+        <Input
+          label="Kartennummer"
+          value={formData.cardNumber}
+          onChange={(e) => setFormData({ ...formData, cardNumber: e.target.value })}
+        />
+
         <Input
           label="BIC"
           value={formData.bic}
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 177c9b58..c73e12f5 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -278,6 +278,7 @@ export interface BankCard {
   customerId: number;
   accountHolder: string;
   iban: string;
+  cardNumber?: string;
   bic?: string;
   bankName?: string;
   expiryDate?: string;