diff --git a/backend/src/modules/banking/types.ts b/backend/src/modules/banking/types.ts
new file mode 100644
index 0000000..47345c3
--- /dev/null
+++ b/backend/src/modules/banking/types.ts
@@ -0,0 +1,38 @@
+// Typen für den Banking-Webhook (angelehnt an FinAPI / GoCardless Bank Account Data)
+
+export interface IncomingBankWebhookPayload {
+  /** Eindeutige ID der Transaktion beim Banking-Provider */
+  transactionId: string;
+  /** IBAN des WG-Kontos, auf dem die Bewegung stattfand */
+  accountIban: string;
+  /** Betrag in Euro, positiv = Eingang */
+  amount: number;
+  currency: 'EUR';
+  /** Verwendungszweck / Referenztext */
+  remittanceInfo: string;
+  /** IBAN des Absenders, falls vorhanden */
+  counterpartyIban?: string;
+  counterpartyName?: string;
+  /** Buchungsdatum (ISO 8601) */
+  bookingDate: string;
+  /** HMAC-Signatur des Providers zur Verifikation */
+  signature: string;
+}
+
+export type MatchConfidence = 'HIGH' | 'MEDIUM' | 'UNCERTAIN';
+
+export interface MatchResult {
+  confidence: MatchConfidence;
+  paymentId?: string;
+  reason: string;
+}
+
+export interface RentTrafficLight {
+  contractId: string;
+  roomNumber: string;
+  tenantName: string;
+  status: 'GREEN' | 'YELLOW' | 'RED';
+  dueDate: string;
+  amountDue: number;
+  amountPaid: number;
+}