diff --git a/README.md b/README.md
index eab5835..d8ce00a 100644
--- a/README.md
+++ b/README.md
@@ -139,9 +139,16 @@ the [MongoDB replication guide](docs/mongodb-replication.md).
 ### Owner email alerts
 
 Set `RESEND_API_KEY` and `EMAIL_FROM` on the web server and download workers to
-send access alerts through [Resend](https://resend.com/docs/api-reference/emails/send-email).
+send access and repository expiration alerts through [Resend](https://resend.com/docs/api-reference/emails/send-email).
 Use a sender address on a domain verified in Resend. `APP_HOSTNAME` sets the
-host used for the connections link in emails.
+host used for links in emails.
+
+After repository expiration completes, the owner receives an email with the
+anonymous repository name, expiration date, and a dashboard link. This uses the
+owner's alert address, falling back to their saved email. Each repository's
+expiration date gets one delivery attempt across workers. Failed or ambiguous
+deliveries retain the guard to prevent duplicate emails and are logged without
+email addresses. Existing expired repositories are not scanned for notifications.
 
 Registration saves a verified GitHub email address, preferring the primary address.
 OAuth requests `user:email`; GitHub App sign-in uses the read-only email permission
diff --git a/src/core/Repository.ts b/src/core/Repository.ts
index 63424ed..d906086 100644
--- a/src/core/Repository.ts
+++ b/src/core/Repository.ts
@@ -4,6 +4,7 @@ import { hasAutomaticUpdates } from "./billing/expiration";
 import { FILE_TREE_BATCH_SIZE, FILE_LISTING_LIMIT, deleteRowsInBatches, clearStagedRowsInBatches } from "./file-tree";
 import { SourceBase, sourceStorageSize } from "./source/Source";
 import { notifyOwnerAccessProblem, withOwnerAccessRecovery } from "./owner-notifications";
+import { notifyRepositoryExpired } from "./repository-expiration-email";
 import AnonymizedPathModel from "./model/anonymized-path";
 import storage from "./storage";
 import { contentGenerationPrefix, contentRetirementMarker } from "./content-generation";
@@ -1045,6 +1046,7 @@ export default class Repository {
         statusDate: new Date(), isReseted: true, size: { storage: 0, file: 0 } },
         $unset: { cleanupToken: "", cleanupUntil: "", pathIndexKey: "", pathIndexBuiltAt: "", sizeComputedAt: "", emptyTreeGeneration: "", retiredTreeGenerations: "", retiredPathIndexKeys: "", retiredContentPrefixes: "", legacyContentCleanupPending: "", stagedFileTrees: "" } }).exec();
       if (result.matchedCount) { this.model.status = RepositoryStatus.EXPIRED; this.model.isReseted = true; this.model.size = { storage: 0, file: 0 }; this.model.sizeComputedAt = undefined; this.model.emptyTreeGeneration = undefined; }
+      if (result.matchedCount) await notifyRepositoryExpired(this.model._id);
     } finally {
       clearInterval(heartbeat);
       await AnonymizedRepositoryModel.updateOne({ _id: this.model._id, cleanupToken: token }, { $unset: { cleanupToken: "", cleanupUntil: "" } }).exec();
diff --git a/src/core/model/anonymizedRepositories/anonymizedRepositories.schema.ts b/src/core/model/anonymizedRepositories/anonymizedRepositories.schema.ts
index ced4491..04bea38 100644
--- a/src/core/model/anonymizedRepositories/anonymizedRepositories.schema.ts
+++ b/src/core/model/anonymizedRepositories/anonymizedRepositories.schema.ts
@@ -5,6 +5,7 @@ import { Schema } from "mongoose";
 const AnonymizedRepositorySchema = new Schema({
   billingManaged: Boolean,
   billingNeverExpiresUntil: Date,
+  expirationEmailClaimedFor: { type: Date, select: false },
   accessAlertGeneration: { type: String, select: false },
   accessAlertClaimedAt: { type: Date, select: false },
   accessAlertAttemptId: { type: String, select: false },
diff --git a/src/core/repository-expiration-email.ts b/src/core/repository-expiration-email.ts
new file mode 100644
index 0000000..82812f2
--- /dev/null
+++ b/src/core/repository-expiration-email.ts
@@ -0,0 +1,46 @@
+import config from "../config";
+import RepositoryModel from "./model/anonymizedRepositories/anonymizedRepositories.model";
+import UserModel from "./model/users/users.model";
+import { notificationEmail } from "./owner-notifications";
+import { createLogger } from "./logger";
+import { RepositoryStatus } from "./types";
+
+const logger = createLogger("repository-expiration-email");
+
+/** Attempt delivery once per repository expiration date, across all workers. */
+export async function notifyRepositoryExpired(id: unknown): Promise<void> {
+  if (!config.RESEND_API_KEY || !config.EMAIL_FROM) return;
+  try {
+    const repo = await RepositoryModel.findOne({ _id: id, status: RepositoryStatus.EXPIRED }).lean();
+    const expirationDate = repo?.options.expirationDate;
+    if (!repo || repo.options.expirationMode === "never" || !expirationDate || expirationDate > new Date()) return;
+    const owner = await UserModel.findOne({ _id: repo.owner, status: { $nin: ["removed", "banned"] } }).lean();
+    const to = owner && notificationEmail(owner.emails, owner.notificationEmail);
+    if (!to) return;
+    const base = /^https?:\/\//.test(config.APP_HOSTNAME) ? config.APP_HOSTNAME : `https://${config.APP_HOSTNAME}`;
+    const url = new URL("/dashboard", base).href;
+    const claim = await RepositoryModel.updateOne({
+      _id: repo._id, owner: repo.owner, status: RepositoryStatus.EXPIRED, statusDate: repo.statusDate,
+      "options.expirationMode": repo.options.expirationMode,
+      "options.expirationDate": expirationDate,
+      expirationEmailClaimedFor: { $ne: expirationDate },
+    }, { $set: { expirationEmailClaimedFor: expirationDate } }).exec();
+    if (!claim.matchedCount) return;
+    // Keep the claim even after a timeout: the provider may have accepted the email.
+    const response = await fetch("https://api.resend.com/emails", {
+      method: "POST",
+      headers: { Authorization: `Bearer ${config.RESEND_API_KEY}`, "Content-Type": "application/json",
+        "Idempotency-Key": `repository-expired/${repo._id}/${expirationDate.getTime()}` },
+      signal: AbortSignal.timeout(15000),
+      body: JSON.stringify({
+        from: config.EMAIL_FROM, to: [to], subject: "Your Anonymous GitHub repository has expired",
+        text: `Your anonymized repository "${repo.repoId}" expired on ${expirationDate.toISOString().slice(0, 10)} (UTC).\n\nIts anonymized content is no longer available.${repo.options.expirationMode === "redirect" ? " Its link now redirects to the original repository." : ""}\n\nOpen your dashboard to manage your repositories:\n${url}\n\nYou are receiving this email because you own this repository on Anonymous GitHub. You can change your alert address on the connections page.\n`,
+      }),
+    });
+    if (response.ok) logger.info("repository expiration email accepted", { repoId: repo.repoId });
+    else logger.warn("repository expiration email delivery failed", { repoId: repo.repoId, httpStatus: response.status });
+  } catch {
+    // Email delivery must not interrupt expiration or expose addresses in logs.
+    logger.warn("repository expiration email unavailable");
+  }
+}
diff --git a/test/repository-expiration-email.test.js b/test/repository-expiration-email.test.js
new file mode 100644
index 0000000..9114ab3
--- /dev/null
+++ b/test/repository-expiration-email.test.js
@@ -0,0 +1,84 @@
+const { expect } = require("chai");
+require("ts-node/register/transpile-only");
+const config = require("../src/config").default;
+const Repo = require("../src/core/model/anonymizedRepositories/anonymizedRepositories.model").default;
+const Users = require("../src/core/model/users/users.model").default;
+const { notifyRepositoryExpired } = require("../src/core/repository-expiration-email");
+
+describe("repository expiration email", function () {
+  const restores = [];
+  const stub = (object, key, value) => { const old = object[key]; restores.push(() => object[key] = old); object[key] = value; };
+  let repo, owner, calls, claims, claimedFor;
+  beforeEach(() => {
+    repo = { _id: "repo-object-id", repoId: "anonymous-name", owner: "owner-id", statusDate: new Date(),
+      options: { expirationMode: "remove", expirationDate: new Date("2025-01-01") } };
+    owner = { emails: [{ email: "default@example.com", default: true }], notificationEmail: "preferred@example.com" };
+    calls = []; claims = []; claimedFor = undefined;
+    stub(config, "RESEND_API_KEY", "test-key"); stub(config, "EMAIL_FROM", "alerts@example.com");
+    stub(config, "APP_HOSTNAME", "https://anonymous.example.com");
+    stub(Repo, "findOne", filter => {
+      expect(filter.status).to.equal("expired");
+      return { lean: async () => repo };
+    });
+    stub(Users, "findOne", filter => {
+      expect(filter.status.$nin).to.deep.equal(["removed", "banned"]);
+      return { lean: async () => owner };
+    });
+    stub(Repo, "updateOne", (filter, update) => ({ exec: async () => {
+      claims.push(filter);
+      const date = update.$set.expirationEmailClaimedFor.getTime();
+      if (claimedFor === date) return { matchedCount: 0 };
+      claimedFor = date;
+      return { matchedCount: 1 };
+    } }));
+    stub(global, "fetch", async (url, options) => { calls.push({ url, options }); return { ok: true }; });
+  });
+  afterEach(() => { while (restores.length) restores.pop()(); });
+
+  it("sends the preferred address an expiration notice with a dashboard link", async () => {
+    await notifyRepositoryExpired(repo._id);
+    const body = JSON.parse(calls[0].options.body);
+    expect(body.to).to.deep.equal(["preferred@example.com"]);
+    expect(body.text).to.include('"anonymous-name" expired on 2025-01-01');
+    expect(body.text).to.include("https://anonymous.example.com/dashboard");
+    expect(body.text).not.to.include("redirects");
+    expect(claims[0]).to.include({ owner: repo.owner, status: "expired", statusDate: repo.statusDate });
+    expect(claims[0]["options.expirationDate"]).to.equal(repo.options.expirationDate);
+  });
+  it("explains redirect expiration", async () => {
+    repo.options.expirationMode = "redirect";
+    await notifyRepositoryExpired(repo._id);
+    expect(JSON.parse(calls[0].options.body).text).to.include("redirects to the original repository");
+  });
+  it("claims concurrent notifications once, and allows a later expiration date", async () => {
+    await Promise.all([notifyRepositoryExpired(repo._id), notifyRepositoryExpired(repo._id)]);
+    expect(calls).to.have.length(1);
+    repo.options.expirationDate = new Date("2025-02-01");
+    await notifyRepositoryExpired(repo._id);
+    expect(calls).to.have.length(2);
+  });
+  for (const scenario of ["disabled", "missing-repo", "never", "future", "missing-owner", "missing-email"]) {
+    it(`skips ${scenario} without claiming delivery`, async () => {
+      if (scenario === "disabled") config.RESEND_API_KEY = "";
+      if (scenario === "missing-repo") repo = null;
+      if (scenario === "never") repo.options.expirationMode = "never";
+      if (scenario === "future") repo.options.expirationDate = new Date(Date.now() + 86400000);
+      if (scenario === "missing-owner") owner = null;
+      if (scenario === "missing-email") owner = {};
+      await notifyRepositoryExpired("repo-object-id");
+      expect(calls).to.have.length(0); expect(claims).to.have.length(0);
+    });
+  }
+  it("does not send when the repository changed before the claim", async () => {
+    stub(Repo, "updateOne", () => ({ exec: async () => ({ matchedCount: 0 }) }));
+    await notifyRepositoryExpired(repo._id);
+    expect(calls).to.have.length(0);
+  });
+  for (const failure of ["timeout", "rejection"]) it(`retains the guard on provider ${failure} without interrupting expiration`, async () => {
+    let attempts = 0;
+    stub(global, "fetch", async () => { attempts++; if (failure === "timeout") throw Error("timeout"); return { ok: false, status: 503 }; });
+    await notifyRepositoryExpired(repo._id);
+    await notifyRepositoryExpired(repo._id);
+    expect(attempts).to.equal(1);
+  });
+});