diff --git a/.changeset/24751-remind-notified-per-person.md b/.changeset/24751-remind-notified-per-person.md
new file mode 100644
index 00000000000..1e73fa3ca8e
--- /dev/null
+++ b/.changeset/24751-remind-notified-per-person.md
@@ -0,0 +1,11 @@
+---
+'@objectstack/plugin-approvals': patch
+---
+
+fix(plugin-approvals): a reminder's `notified` counts each approver address once, not once per slate slot
+
+Clause-②: no
+
+`POST /api/v1/approvals/requests/:id/remind` (`ApprovalService.remind()`) answers `notified` as the number of reminders it handed to messaging: one per distinct approver address on the pending slate. A `per_group` slate lists a person once per group they resolved into, and `pending_approvers` keeps every one of those slots until the first vote, so a person placed in two groups was counted twice while messaging delivered them one reminder. They are now reminded once and counted once, the rule the opening `approval.requested` notice already applies.
+
+A user id and the same account's email are still two addresses: the person holds two slots and receives two reminders, exactly as at the opening. Unchanged: who is reminded, each reminder's topic, payload, deep link and dedup key, the throttle, the submitter check, the `remind` audit row, and `position:*`-style literals, which still notify no one and add nothing to the count.
diff --git a/packages/plugins/plugin-approvals/src/approval-service.ts b/packages/plugins/plugin-approvals/src/approval-service.ts
index 3382971460c..ea15dca7233 100644
--- a/packages/plugins/plugin-approvals/src/approval-service.ts
+++ b/packages/plugins/plugin-approvals/src/approval-service.ts
@@ -5482,9 +5482,19 @@ export class ApprovalService implements IApprovalService {
     // approver: a reminder names no channel, messaging's default materializes
     // it in the in-app inbox, and the inbox row carries the title, the body and
     // the deep link below, never links. The deep link is the approver's way in.
+    //
+    // [#24751] Each address once — the opening's rule (`openedOn`). A slate
+    // lists a person once per group they resolved into (per_group tagging), and
+    // `pending_approvers` keeps every one of those slots until the first vote,
+    // so one id can stand there twice. Messaging delivers that person ONE
+    // reminder (both emits carry the same dedup key), so counting per slot
+    // answered a `notified` the inbox contradicts. `notified` is the number of
+    // reminders handed over: one per distinct address. A user id and the same
+    // account's email are two addresses here, exactly as at the opening — two
+    // slots the person takes separately, and two reminders delivered.
     const subject = this.nameSubjectRecord(raw.object_name, raw.record_id);
     let notified = 0;
-    const concrete = pending.filter(a => a && !a.includes(':'));
+    const concrete = new Set(pending.filter(a => a && !a.includes(':')));
     const literals = pending.filter(a => a && a.includes(':'));
     for (const approver of concrete) {
       notified += await this.notify({
diff --git a/packages/plugins/plugin-approvals/src/remind-notified-per-person.integration.test.ts b/packages/plugins/plugin-approvals/src/remind-notified-per-person.integration.test.ts
new file mode 100644
index 00000000000..3dc9f2789ce
--- /dev/null
+++ b/packages/plugins/plugin-approvals/src/remind-notified-per-person.integration.test.ts
@@ -0,0 +1,248 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * A reminder's `notified` counts the reminders it hands over — one per
+ * distinct approver address, never one per slate slot (#24751).
+ *
+ * ## The defect
+ *
+ * A `per_group` slate lists a person once per group they resolved into, and
+ * `pending_approvers` keeps every one of those slots until the first vote. So
+ * one user placed in two groups stands on the stored slate twice. The opening
+ * fan-out told that person once (`openedOn`, a Set); `remind()` looped over
+ * the raw slots and added each `notify()` result, so `POST …/remind` answered
+ * `notified: 2` while messaging stored ONE reminder for them — the second emit
+ * carries the same dedup key. The console shows that number to the submitter
+ * ("Reminder sent to N approver(s)").
+ *
+ * ## What this pins
+ *
+ * Driven through the real `ApprovalService` on a real `ObjectQL` over
+ * `SqlDriver` (better-sqlite3, in-memory, real DDL), with the real
+ * `AutomationEngine` running each flow and the real approval node opening the
+ * request, and the messaging surface recording every emit it is handed:
+ *
+ * - one approver listed in two groups: the stored slate really lists them
+ *   twice (the scene), the reminder hands messaging ONE reminder for them and
+ *   answers `notified: 1`;
+ * - the same holds for an approver authored as an email in both groups;
+ * - control: two distinct approvers get a reminder each, `notified: 2`;
+ * - a `position:*` literal the slate keeps beside a person adds nothing — no
+ *   emit, no count — while the person beside it is still reminded;
+ * - an account's id and its email are two addresses, at the reminder exactly
+ *   as at the opening: two reminders, `notified: 2`;
+ * - on every slate, the reminder reaches exactly the addresses the opening's
+ *   `approval.requested` reached.
+ *
+ * Unchanged by the fix and held here too: each reminder's topic, deep link and
+ * per-approver dedup key, and the one `remind` audit row per reminder.
+ */
+
+import { describe, it, expect, beforeAll, afterAll } from 'vitest';
+import { ObjectQL } from '@objectstack/objectql';
+import { SqlDriver } from '@objectstack/driver-sql';
+import { AutomationEngine } from '@objectstack/service-automation';
+import type { EngineQueryOptions } from '@objectstack/spec/data';
+import { ApprovalService } from './approval-service.js';
+import { ApprovalsServicePlugin } from './approvals-plugin.js';
+import { registerApprovalNode } from './approval-node.js';
+
+const SYSTEM = { isSystem: true, positions: [], permissions: [] } as any;
+const asUser = (userId: string) => ({ userId, positions: [], permissions: [] }) as any;
+const silent = { info: () => {}, warn: () => {}, error: () => {}, debug: () => {} } as any;
+
+const ORG = 'org_remind';
+const ALICE_EMAIL = 'alice@example.com';
+
+const USERS = [
+  { id: 'u_sub', name: 'Sam Submitter', email: 'sam@example.com' },
+  { id: 'u_alice', name: 'Alice', email: ALICE_EMAIL },
+  { id: 'u_bob', name: 'Bob', email: 'bob@example.com' },
+];
+
+const sysUser = {
+  name: 'sys_user',
+  label: 'User',
+  fields: {
+    id: { name: 'id', label: 'Id', type: 'text' as const, primaryKey: true },
+    name: { name: 'name', label: 'Name', type: 'text' as const },
+    email: { name: 'email', label: 'Email', type: 'text' as const },
+  },
+};
+const deal = {
+  name: 'crm_deal',
+  label: 'Deal',
+  fields: {
+    id: { name: 'id', label: 'Id', type: 'text' as const, primaryKey: true },
+    title: { name: 'title', label: 'Title', type: 'text' as const },
+  },
+};
+
+/** The plugin's own object definitions, as its manifest registers them. */
+async function packageObjects(): Promise<any[]> {
+  let manifest: any;
+  const ctx: any = {
+    getService: (name: string) => {
+      if (name === 'manifest') return { register: (m: any) => { manifest = m; } };
+      throw new Error(`no service '${name}'`);
+    },
+    logger: silent,
+  };
+  await new ApprovalsServicePlugin().init(ctx);
+  return manifest.objects;
+}
+
+/** A `user` approver in a named group of a `per_group` slate. */
+const inGroup = (value: string, group: string) => ({ type: 'user', value, group });
+
+/** One `per_group` approval step between start and two ends. */
+function perGroup(name: string, approvers: Array<Record<string, unknown>>): any {
+  return {
+    name, label: name, type: 'autolaunched',
+    nodes: [
+      { id: 'start', type: 'start', label: 'Start' },
+      { id: 'review', type: 'approval', label: 'Review', config: { approvers, behavior: 'per_group' } },
+      { id: 'ok', type: 'end', label: 'Approved' },
+      { id: 'no', type: 'end', label: 'Rejected' },
+    ],
+    edges: [
+      { id: 'e1', source: 'start', target: 'review' },
+      { id: 'e2', source: 'review', target: 'ok', label: 'approve' },
+      { id: 'e3', source: 'review', target: 'no', label: 'reject' },
+    ],
+  };
+}
+
+/** The slates under test — each its own flow, so each request is its own reminder window. */
+const SLATES: Record<string, Array<Record<string, unknown>>> = {
+  twice_by_id: [inGroup('u_alice', 'first'), inGroup('u_alice', 'second')],
+  twice_by_email: [inGroup(ALICE_EMAIL, 'first'), inGroup(ALICE_EMAIL, 'second')],
+  two_people: [inGroup('u_alice', 'first'), inGroup('u_bob', 'second')],
+  // `position:nobody_holds` stays on the slate as its `type:value` literal.
+  person_and_literal: [inGroup('u_alice', 'first'), { type: 'position', value: 'nobody_holds', group: 'second' }],
+  id_and_email: [inGroup('u_alice', 'first'), inGroup(ALICE_EMAIL, 'second')],
+};
+
+interface Emitted {
+  topic: string;
+  audience: string[];
+  dedupKey?: string;
+  source?: { object: string; id: string };
+  payload?: Record<string, unknown>;
+}
+
+describe('a reminder counts the reminders it hands over, one per distinct approver address', () => {
+  let engine: ObjectQL;
+  let automation: AutomationEngine;
+  let svc: ApprovalService;
+  let now = Date.parse('2026-10-20T09:00:00.000Z');
+  const emits: Emitted[] = [];
+
+  /** Start `flow` on a fresh deal as the submitter; answer the request it opened. */
+  const submit = async (flow: string): Promise<any> => {
+    const record = { id: `D_${flow}`, title: flow, organization_id: ORG };
+    await engine.insert('crm_deal', record, { context: SYSTEM } as any);
+    const run = await automation.execute(flow, { object: 'crm_deal', record, userId: 'u_sub' } as any);
+    expect(run.status, `${flow} paused on its approval step`).toBe('paused');
+    const rows: any[] = await engine.find('sys_approval_request', {
+      where: { record_id: record.id, status: 'pending' }, context: SYSTEM,
+    } satisfies EngineQueryOptions);
+    expect(rows.length, `one pending request on ${record.id}`).toBe(1);
+    return rows[0];
+  };
+  /** The audiences of one topic's emits about one request, in emit order. */
+  const audiencesOf = (topic: string, requestId: string) =>
+    emits.filter((e) => e.topic === topic && e.source?.id === requestId).map((e) => e.audience);
+  /**
+   * Submit on `flow`, then send its reminder as the submitter. Every slate also
+   * holds the reminder to the opening's rule: it reaches exactly the addresses
+   * `approval.requested` reached (none of these slates has an out-of-office hop).
+   */
+  const remindOn = async (flow: string) => {
+    const req = await submit(flow);
+    const stored = String(req.pending_approvers ?? '').split(',').filter(Boolean);
+    const out = await svc.remind(req.id, { actorId: 'u_sub' }, asUser('u_sub'));
+    const reminders = audiencesOf('approval.reminder', req.id);
+    const opened = audiencesOf('approval.requested', req.id);
+    expect(opened.length, `${flow}: the opening told someone`).toBeGreaterThan(0);
+    // Soft, so a broken fan-out still reaches the case's own `notified` assertion.
+    expect.soft(reminders, `${flow}: the reminder reached whom the opening reached`).toEqual(opened);
+    return { req, stored, notified: out.notified, reminders };
+  };
+
+  beforeAll(async () => {
+    engine = new ObjectQL();
+    engine.registerDriver(new SqlDriver({
+      client: 'better-sqlite3', connection: { filename: ':memory:' }, useNullAsDefault: true,
+    }), true);
+    await engine.init();
+    for (const def of [sysUser, deal, ...(await packageObjects())]) {
+      engine.registry.registerObject(def as any, 'approvals-test', 'approvals-test');
+    }
+    await engine.syncSchemas();
+    for (const u of USERS) await engine.insert('sys_user', u, { context: SYSTEM } as any);
+
+    automation = new AutomationEngine(silent);
+    svc = new ApprovalService({
+      engine: engine as any,
+      clock: { now: () => new Date(now += 1000) },
+      logger: silent,
+    });
+    svc.attachAutomation(automation as any);
+    svc.attachMessaging({ async emit(input) { emits.push(input as Emitted); } });
+    registerApprovalNode(automation as any, svc, silent);
+
+    for (const [name, approvers] of Object.entries(SLATES)) automation.registerFlow(name, perGroup(name, approvers));
+  });
+
+  afterAll(async () => {
+    try { await engine?.destroy(); } catch { /* noop */ }
+  });
+
+  it('an approver the slate lists in two groups is handed one reminder and counted once', async () => {
+    const { req, stored, notified, reminders } = await remindOn('twice_by_id');
+    // The scene: the stored slate really lists her twice, so a count of 1 is the rule, not an empty slate.
+    expect(stored).toEqual(['u_alice', 'u_alice']);
+
+    expect(notified).toBe(1);
+    expect(reminders).toEqual([['u_alice']]);
+
+    // Unchanged: the reminder itself — topic, deep link, per-approver dedup key — and its one audit row.
+    const [reminder] = emits.filter((e) => e.topic === 'approval.reminder' && e.source?.id === req.id);
+    expect(reminder.payload?.actionUrl).toBe(`/system/approvals?request=${encodeURIComponent(req.id)}`);
+    expect(reminder.dedupKey).toMatch(new RegExp(`^approval-remind-${req.id}-.+-u_alice$`));
+    const audit: any[] = await engine.find('sys_approval_action', {
+      where: { request_id: req.id, action: 'remind' }, context: SYSTEM,
+    } satisfies EngineQueryOptions);
+    expect(audit.map((a) => a.actor_id)).toEqual(['u_sub']);
+  });
+
+  it('an approver authored as the same email in two groups is handed one reminder and counted once', async () => {
+    const { stored, notified, reminders } = await remindOn('twice_by_email');
+    expect(stored).toEqual([ALICE_EMAIL, ALICE_EMAIL]);
+    expect(notified).toBe(1);
+    expect(reminders).toEqual([[ALICE_EMAIL]]);
+  });
+
+  it('control: two distinct approvers are each handed a reminder, and both are counted', async () => {
+    const { stored, notified, reminders } = await remindOn('two_people');
+    expect(stored).toEqual(['u_alice', 'u_bob']);
+    expect(notified).toBe(2);
+    expect(reminders).toEqual([['u_alice'], ['u_bob']]);
+  });
+
+  it('a position:* literal on the slate adds nothing, and the person beside it is still reminded', async () => {
+    const { stored, notified, reminders } = await remindOn('person_and_literal');
+    expect(stored).toEqual(['u_alice', 'position:nobody_holds']);
+    // The literal names no one: it adds nothing to the count, and no emit carries it.
+    expect(notified).toBe(1);
+    expect(reminders).toEqual([['u_alice']]);
+  });
+
+  it("an account's id and its email are two addresses: two reminders, as at the opening", async () => {
+    const { stored, notified, reminders } = await remindOn('id_and_email');
+    expect(stored).toEqual(['u_alice', ALICE_EMAIL]);
+    expect(notified).toBe(2);
+    expect(reminders).toEqual([['u_alice'], [ALICE_EMAIL]]);
+  });
+});