diff --git a/src/__tests__/account-data.test.ts b/src/__tests__/account-data.test.ts
new file mode 100644
index 0000000..a2e7261
--- /dev/null
+++ b/src/__tests__/account-data.test.ts
@@ -0,0 +1,91 @@
+/**
+ * DSGVO-Pfade rund um das Empfehlungsprogramm: Datenauskunft (gdpr-export.ts)
+ * und Kontolöschung (delete-account.ts).
+ */
+
+import { describe, it, expect, vi } from "vitest";
+
+vi.mock("server-only", () => ({}));
+const mockDeleteUser = vi.fn().mockResolvedValue(undefined);
+vi.mock("@clerk/nextjs/server", () => ({
+  clerkClient: vi.fn().mockResolvedValue({
+    users: { getUser: vi.fn().mockResolvedValue(null), deleteUser: (...a: unknown[]) => mockDeleteUser(...a) },
+  }),
+}));
+vi.mock("@/lib/supabase-storage", () => ({ deleteFiles: vi.fn().mockResolvedValue(undefined) }));
+vi.mock("@/lib/media-url", () => ({ getMediaUrl: (key: string) => `media/${key}` }));
+vi.mock("@/lib/avatar-url", () => ({ getAvatarUrl: (key: string | null) => (key ? `avatar/${key}` : null) }));
+
+import { createMockPrisma } from "@/__tests__/helpers/prisma-mock";
+import { deleteOwnerAccount } from "@/lib/delete-account";
+import { buildDataExport } from "@/lib/gdpr-export";
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const asDb = (m: ReturnType<typeof createMockPrisma>) => m as any;
+
+describe("deleteOwnerAccount", () => {
+  it("removes the deleted owner's id from other owners' referral and legacy invite links", async () => {
+    const prisma = createMockPrisma();
+    prisma.pet.findMany.mockResolvedValue([]);
+    prisma.pet.deleteMany.mockResolvedValue({ count: 0 });
+    prisma.owner.updateMany.mockResolvedValue({ count: 2 });
+    prisma.owner.delete.mockResolvedValue({});
+
+    await deleteOwnerAccount(asDb(prisma), "owner-gone");
+
+    expect(prisma.owner.updateMany).toHaveBeenCalledWith({
+      where: { invitedById: "owner-gone" },
+      data: { invitedById: null },
+    });
+    expect(prisma.inviteCode.updateMany).toHaveBeenCalledWith({
+      where: { usedById: "owner-gone" },
+      data: { usedById: null },
+    });
+    expect(mockDeleteUser).toHaveBeenCalledWith("owner-gone");
+  });
+});
+
+describe("buildDataExport — referral program", () => {
+  it("includes code, ranks and invites but names other people only by pet name", async () => {
+    const prisma = createMockPrisma();
+    prisma.owner.findUnique.mockResolvedValue({
+      id: "owner-1",
+      createdAt: new Date("2026-09-01"),
+      invitedById: "user_inviter_secret_id",
+      invitedAt: new Date("2026-09-02"),
+      referralQualifiedAt: new Date("2026-09-03"),
+      referralFlaggedAt: null,
+      referralRevokedAt: null,
+      referralCode: "LUNA-7K3M",
+      qualifiedReferralCount: 1,
+      referralPerks: ["PROFILE_RING"],
+      acquisitionSource: "FRIENDS",
+      acquisitionAnsweredAt: new Date("2026-09-02"),
+      legalAcknowledgedAt: null,
+      contentRightsConsentedAt: null,
+      dataProcessingConsentedAt: null,
+      ban: null,
+      adminRole: null,
+      pets: [],
+      rankAchievements: [{ achievedAt: new Date("2026-09-10"), rank: { nameDe: "Pfotenfreund", threshold: 1 } }],
+      issuedInvites: [],
+    });
+    prisma.pet.findFirst.mockResolvedValue({ name: "Bubi" });
+    prisma.owner.findMany.mockResolvedValue([
+      { invitedAt: new Date("2026-09-09"), referralQualifiedAt: new Date("2026-09-10"), referralRevokedAt: null, pets: [{ name: "Kiki" }] },
+    ]);
+
+    const data = await buildDataExport(asDb(prisma), "owner-1");
+
+    expect(data?.referralProgram).toMatchObject({
+      ownCode: "LUNA-7K3M",
+      acquisitionSource: "FRIENDS",
+      invitedBy: { petName: "Bubi" },
+      countedInvites: 1,
+      invitesMade: [{ petName: "Kiki" }],
+      ranksReached: [{ rank: "Pfotenfreund", threshold: 1 }],
+      currentPerks: ["PROFILE_RING"],
+    });
+    expect(JSON.stringify(data)).not.toContain("user_inviter_secret_id");
+  });
+});
diff --git a/src/__tests__/helpers/prisma-mock.ts b/src/__tests__/helpers/prisma-mock.ts
index bf3a139..27e7de9 100644
--- a/src/__tests__/helpers/prisma-mock.ts
+++ b/src/__tests__/helpers/prisma-mock.ts
@@ -21,6 +21,7 @@ interface MockPetClient {
   findFirst: MockFn;
   update: MockFn;
   delete: MockFn;
+  deleteMany: MockFn;
   count: MockFn;
 }
 
@@ -31,12 +32,15 @@ interface MockOwnerClient {
   create: MockFn;
   update: MockFn;
   updateMany: MockFn;
+  delete: MockFn;
   count: MockFn;
 }
 
 interface MockInviteCodeClient {
   count: MockFn;
   createMany: MockFn;
+  deleteMany: MockFn;
+  updateMany: MockFn;
 }
 
 interface MockLegalDocumentVersionClient {
@@ -410,6 +414,7 @@ export function createMockPrisma(): MockPrismaClient {
       findFirst: vi.fn(),
       update: vi.fn(),
       delete: vi.fn(),
+      deleteMany: vi.fn(),
       count: vi.fn(),
     },
     owner: {
@@ -419,6 +424,7 @@ export function createMockPrisma(): MockPrismaClient {
       create: vi.fn(),
       update: vi.fn(),
       updateMany: vi.fn(),
+      delete: vi.fn(),
       count: vi.fn(),
     },
     // Legacy InviteCode table (pre-referral-program one-time codes) — only
@@ -426,6 +432,8 @@ export function createMockPrisma(): MockPrismaClient {
     inviteCode: {
       count: vi.fn().mockResolvedValue(0),
       createMany: vi.fn().mockResolvedValue({ count: 0 }),
+      deleteMany: vi.fn().mockResolvedValue({ count: 0 }),
+      updateMany: vi.fn().mockResolvedValue({ count: 0 }),
     },
     legalDocumentVersion: {
       create: vi.fn(),
diff --git a/src/__tests__/referrals-router.test.ts b/src/__tests__/referrals-router.test.ts
index 4f6089e..aea2b4f 100644
--- a/src/__tests__/referrals-router.test.ts
+++ b/src/__tests__/referrals-router.test.ts
@@ -77,17 +77,17 @@ describe("referrals.setAcquisitionSource", () => {
 describe("referrals.onboardingState", () => {
   it("shows the step once, inside the redeem window", async () => {
     const { caller, prisma } = await createCaller();
-    prisma.owner.findUnique.mockResolvedValue({ createdAt: new Date(), invitedById: null, acquisitionAnsweredAt: null });
+    prisma.owner.findUnique.mockResolvedValue({ createdAt: new Date(), invitedAt: null, acquisitionAnsweredAt: null });
     expect(await caller.referrals.onboardingState()).toEqual({ showStep: true, canRedeem: true });
 
-    prisma.owner.findUnique.mockResolvedValue({ createdAt: new Date(), invitedById: null, acquisitionAnsweredAt: new Date() });
+    prisma.owner.findUnique.mockResolvedValue({ createdAt: new Date(), invitedAt: null, acquisitionAnsweredAt: new Date() });
     expect(await caller.referrals.onboardingState()).toEqual({ showStep: false, canRedeem: true });
   });
 
   it("hides everything for owners older than the window", async () => {
     const { caller, prisma } = await createCaller();
     const old = new Date(Date.now() - 30 * 24 * 60 * 60 * 1000);
-    prisma.owner.findUnique.mockResolvedValue({ createdAt: old, invitedById: null, acquisitionAnsweredAt: null });
+    prisma.owner.findUnique.mockResolvedValue({ createdAt: old, invitedAt: null, acquisitionAnsweredAt: null });
     expect(await caller.referrals.onboardingState()).toEqual({ showStep: false, canRedeem: false });
   });
 });
diff --git a/src/__tests__/referrals.test.ts b/src/__tests__/referrals.test.ts
index c042eee..b253537 100644
--- a/src/__tests__/referrals.test.ts
+++ b/src/__tests__/referrals.test.ts
@@ -151,7 +151,7 @@ describe("redeemReferralCode", () => {
 
     expect(result).toEqual({ inviterPetName: "Bubi" });
     expect(mockPrisma.owner.updateMany).toHaveBeenCalledWith({
-      where: { id: "owner-invitee", invitedById: null },
+      where: { id: "owner-invitee", invitedById: null, invitedAt: null },
       data: { invitedById: "owner-inviter", invitedAt: NOW },
     });
     expect(mockPrisma.follow.upsert).toHaveBeenCalledTimes(2);
@@ -196,6 +196,14 @@ describe("redeemReferralCode", () => {
     );
   });
 
+  it("rejects a second redemption after the inviter's account was deleted", async () => {
+    // delete-account.ts leert invitedById, invitedAt bleibt als Marker stehen.
+    const mockPrisma = setupRedeem({ invitee: { createdAt: NOW, invitedById: null, invitedAt: new Date(NOW.getTime() - DAY) } });
+    await expect(redeemReferralCode(asDb(mockPrisma), "owner-invitee", "BUBI-7K3M", NOW)).rejects.toThrow(
+      REFERRAL_ERRORS.ALREADY_REDEEMED
+    );
+  });
+
   it("lets only one of two concurrent redemptions win", async () => {
     const mockPrisma = setupRedeem();
     mockPrisma.owner.updateMany.mockResolvedValue({ count: 0 });
diff --git a/src/lib/delete-account.ts b/src/lib/delete-account.ts
index 4074935..f03d84f 100644
--- a/src/lib/delete-account.ts
+++ b/src/lib/delete-account.ts
@@ -6,7 +6,8 @@ import { deleteFiles } from "@/lib/supabase-storage";
 /**
  * Permanently deletes an Owner and everything cascading from their pets
  * (posts, comments, reactions, follows, notifications, etc.), storage files,
- * issued invite codes, and the Clerk account itself. Irreversible — shared
+ * issued invite codes, referral rank achievements (cascade), references to
+ * this owner in other owners' invitedById, and the Clerk account itself. Irreversible — shared
  * by the self-service delete route and the admin-triggered GDPR erasure
  * action, so both paths stay in sync.
  */
@@ -44,6 +45,13 @@ export async function deleteOwnerAccount(prisma: PrismaClient, ownerId: string):
 
   await prisma.inviteCode.deleteMany({ where: { issuedById: ownerId } });
 
+  // Empfehlungsprogramm: die Clerk-ID der gelöschten Person darf nicht bei
+  // anderen Ownern stehen bleiben. Gezählte Einladungen bleiben gezählt
+  // (referralQualifiedAt), nur die Zuordnung zur gelöschten Person entfällt.
+  // Gleiches gilt für Einmal-Codes aus der Beta, die diese Person eingelöst hat.
+  await prisma.owner.updateMany({ where: { invitedById: ownerId }, data: { invitedById: null } });
+  await prisma.inviteCode.updateMany({ where: { usedById: ownerId }, data: { usedById: null } });
+
   // Cascades AdminRole + UserBan + Warning
   await prisma.owner.delete({ where: { id: ownerId } });
 
diff --git a/src/lib/gdpr-export.ts b/src/lib/gdpr-export.ts
index 056a3eb..b53e82e 100644
--- a/src/lib/gdpr-export.ts
+++ b/src/lib/gdpr-export.ts
@@ -16,9 +16,14 @@ import { getAvatarUrl } from "@/lib/avatar-url";
  * this export.
  *
  * Scope: covers the social graph, health records, messages, moderation
- * history, and consent timestamps. Advertisement interactions and issued
- * invite codes are NOT yet included — flagged as a known gap rather than
- * silently omitted (see the emailed cover note).
+ * history, consent timestamps, the referral program (own code, who invited
+ * this owner, invites made, ranks, acquisition answer) and legacy one-time
+ * invite codes. Advertisement interactions are NOT yet included — flagged
+ * as a known gap rather than silently omitted (see the emailed cover note).
+ *
+ * Other owners are only ever referenced by their pet's name, never by
+ * their Clerk userId (invitedById, invitee ids) — that id is the other
+ * person's data, not this owner's.
  */
 export async function buildDataExport(prisma: PrismaClient, ownerId: string) {
   const [owner, clerkUser] = await Promise.all([
@@ -63,6 +68,11 @@ export async function buildDataExport(prisma: PrismaClient, ownerId: string) {
         },
         ban: true,
         adminRole: true,
+        rankAchievements: {
+          orderBy: { achievedAt: "asc" },
+          include: { rank: { select: { nameDe: true, threshold: true } } },
+        },
+        issuedInvites: { select: { code: true, createdAt: true, usedAt: true, revoked: true } },
       },
     }),
     (await clerkClient()).users.getUser(ownerId).catch(() => null),
@@ -70,15 +80,35 @@ export async function buildDataExport(prisma: PrismaClient, ownerId: string) {
 
   if (!owner) return null;
 
+  const [invitedByPet, invitees] = await Promise.all([
+    owner.invitedById
+      ? prisma.pet.findFirst({
+          where: { ownerId: owner.invitedById },
+          orderBy: { createdAt: "asc" },
+          select: { name: true },
+        })
+      : null,
+    prisma.owner.findMany({
+      where: { invitedById: ownerId },
+      orderBy: { invitedAt: "asc" },
+      select: {
+        invitedAt: true,
+        referralQualifiedAt: true,
+        referralRevokedAt: true,
+        pets: { orderBy: { createdAt: "asc" }, take: 1, select: { name: true } },
+      },
+    }),
+  ]);
+
   return {
     exportedAt: new Date().toISOString(),
     scopeNote:
-      "Enthält Social-Graph-, Health- und Nachrichtendaten sowie Consent-Zeitstempel. " +
-      "Werbeanzeigen-Interaktionen und ausgegebene Einladungscodes sind aktuell noch nicht enthalten.",
+      "Enthält Social-Graph-, Health- und Nachrichtendaten, Consent-Zeitstempel, das Empfehlungsprogramm " +
+      "und frühere Einladungscodes. Werbeanzeigen-Interaktionen sind aktuell noch nicht enthalten. " +
+      "Andere Personen werden nur über den Namen ihres Tiers genannt.",
     account: {
       ownerId: owner.id,
       createdAt: owner.createdAt,
-      invitedById: owner.invitedById,
       legalAcknowledgedAt: owner.legalAcknowledgedAt,
       contentRightsConsentedAt: owner.contentRightsConsentedAt,
       dataProcessingConsentedAt: owner.dataProcessingConsentedAt,
@@ -94,6 +124,34 @@ export async function buildDataExport(prisma: PrismaClient, ownerId: string) {
       ban: owner.ban,
       adminRole: owner.adminRole,
     },
+    referralProgram: {
+      ownCode: owner.referralCode,
+      acquisitionSource: owner.acquisitionSource,
+      acquisitionAnsweredAt: owner.acquisitionAnsweredAt,
+      invitedBy: owner.invitedById
+        ? {
+            petName: invitedByPet?.name ?? null,
+            invitedAt: owner.invitedAt,
+            countedAt: owner.referralQualifiedAt,
+            flaggedForReviewAt: owner.referralFlaggedAt,
+            revokedAt: owner.referralRevokedAt,
+          }
+        : null,
+      countedInvites: owner.qualifiedReferralCount,
+      invitesMade: invitees.map((i) => ({
+        petName: i.pets[0]?.name ?? null,
+        invitedAt: i.invitedAt,
+        countedAt: i.referralQualifiedAt,
+        revokedAt: i.referralRevokedAt,
+      })),
+      ranksReached: owner.rankAchievements.map((a) => ({
+        rank: a.rank.nameDe,
+        threshold: a.rank.threshold,
+        reachedAt: a.achievedAt,
+      })),
+      currentPerks: owner.referralPerks,
+      legacyInviteCodes: owner.issuedInvites,
+    },
     pets: owner.pets.map((pet) => ({
       id: pet.id,
       name: pet.name,
diff --git a/src/lib/referrals.ts b/src/lib/referrals.ts
index 92bb6e3..14fec26 100644
--- a/src/lib/referrals.ts
+++ b/src/lib/referrals.ts
@@ -140,10 +140,11 @@ export async function redeemReferralCode(
 
   const owner = await prisma.owner.findUnique({
     where: { id: ownerId },
-    select: { createdAt: true, invitedById: true },
+    select: { createdAt: true, invitedById: true, invitedAt: true },
   });
   if (!owner) fail("PRECONDITION_FAILED", REFERRAL_ERRORS.NO_PET);
-  if (owner.invitedById) fail("CONFLICT", REFERRAL_ERRORS.ALREADY_REDEEMED);
+  // invitedAt zählt mit: wird ein Einladender gelöscht, leert delete-account.ts nur invitedById.
+  if (owner.invitedById || owner.invitedAt) fail("CONFLICT", REFERRAL_ERRORS.ALREADY_REDEEMED);
   if (now.getTime() - owner.createdAt.getTime() > settings.redeemWindowDays * DAY_MS) {
     fail("PRECONDITION_FAILED", REFERRAL_ERRORS.WINDOW_EXPIRED);
   }
@@ -161,7 +162,7 @@ export async function redeemReferralCode(
 
   // Bewacht mit invitedById: null — zwei parallele Einlösungen können nicht beide gewinnen.
   const claimed = await prisma.owner.updateMany({
-    where: { id: ownerId, invitedById: null },
+    where: { id: ownerId, invitedById: null, invitedAt: null },
     data: { invitedById: inviter.id, invitedAt: now },
   });
   if (claimed.count === 0) fail("CONFLICT", REFERRAL_ERRORS.ALREADY_REDEEMED);
diff --git a/src/trpc/routers/referrals.ts b/src/trpc/routers/referrals.ts
index f515566..1211b3f 100644
--- a/src/trpc/routers/referrals.ts
+++ b/src/trpc/routers/referrals.ts
@@ -59,6 +59,7 @@ export const referralsRouter = router({
         select: {
           createdAt: true,
           invitedById: true,
+          invitedAt: true,
           qualifiedReferralCount: true,
           referralRankId: true,
           referralPerks: true,
@@ -99,8 +100,8 @@ export const referralsRouter = router({
       achievedRankIds: [...achievedIds],
       nextRankId: next?.id ?? null,
       canRedeem:
-        settings.programActive && !!owner && !owner.invitedById && !!redeemDeadline && redeemDeadline > new Date(),
-      wasInvited: !!owner?.invitedById,
+        settings.programActive && !!owner && !owner.invitedAt && !!redeemDeadline && redeemDeadline > new Date(),
+      wasInvited: !!owner?.invitedAt,
       invitees: invitees.map((invitee) => ({
         pet: invitee.pets[0] ?? null,
         invitedAt: invitee.invitedAt,
@@ -123,7 +124,7 @@ export const referralsRouter = router({
     const [owner, settings] = await Promise.all([
       ctx.prisma.owner.findUnique({
         where: { id: ctx.userId },
-        select: { createdAt: true, invitedById: true, acquisitionAnsweredAt: true },
+        select: { createdAt: true, invitedAt: true, acquisitionAnsweredAt: true },
       }),
       getReferralSettings(ctx.prisma),
     ]);
@@ -131,7 +132,7 @@ export const referralsRouter = router({
     const withinWindow = Date.now() - owner.createdAt.getTime() <= settings.redeemWindowDays * DAY_MS;
     return {
       showStep: !owner.acquisitionAnsweredAt && withinWindow,
-      canRedeem: settings.programActive && !owner.invitedById && withinWindow,
+      canRedeem: settings.programActive && !owner.invitedAt && withinWindow,
     };
   }),