diff --git a/apps/api/src/routes/admin-users.ts b/apps/api/src/routes/admin-users.ts
index f6886ae..fe440e9 100644
--- a/apps/api/src/routes/admin-users.ts
+++ b/apps/api/src/routes/admin-users.ts
@@ -87,3 +87,36 @@ adminUsersRoutes.post('/api/admin/users/:id/role', async (c) => {
   const [updated] = await db.select().from(user).where(eq(user.id, id));
   return c.json(toListItem(updated));
 });
+
+adminUsersRoutes.post('/api/admin/users/:id/deactivate', async (c) => {
+  const id = c.req.param('id');
+  const caller = await getSessionUser(c);
+  const [target] = await db.select().from(user).where(eq(user.id, id));
+  if (!target) return c.json({ error: 'Gebruiker niet gevonden' }, 404);
+
+  if (id === caller?.id) return c.json({ error: 'Je kunt jezelf niet deactiveren.' }, 400);
+  if (target.role === 'admin' && (await activeAdminsExcluding(id)) === 0) {
+    return c.json({ error: 'Er moet minstens één actieve beheerder blijven.' }, 400);
+  }
+
+  await db
+    .update(user)
+    .set({ banned: true, banReason: null, banExpires: null })
+    .where(eq(user.id, id));
+  await db.delete(session).where(eq(session.userId, id)); // kill any live token
+  const [updated] = await db.select().from(user).where(eq(user.id, id));
+  return c.json(toListItem(updated));
+});
+
+adminUsersRoutes.post('/api/admin/users/:id/reactivate', async (c) => {
+  const id = c.req.param('id');
+  const [target] = await db.select().from(user).where(eq(user.id, id));
+  if (!target) return c.json({ error: 'Gebruiker niet gevonden' }, 404);
+
+  await db
+    .update(user)
+    .set({ banned: false, banReason: null, banExpires: null })
+    .where(eq(user.id, id));
+  const [updated] = await db.select().from(user).where(eq(user.id, id));
+  return c.json(toListItem(updated));
+});
diff --git a/apps/api/test/admin-users.test.ts b/apps/api/test/admin-users.test.ts
index 721e9a7..9a81752 100644
--- a/apps/api/test/admin-users.test.ts
+++ b/apps/api/test/admin-users.test.ts
@@ -193,3 +193,103 @@ describe('POST /api/admin/users/:id/role', () => {
     expect(res.status).toBe(200);
   });
 });
+
+describe('deactivate / reactivate', () => {
+  async function signIn(app: Hono, email: string, password: string): Promise<number> {
+    const res = await app.request('/api/auth/sign-in/email', {
+      method: 'POST',
+      headers: { 'content-type': 'application/json' },
+      body: JSON.stringify({ email, password }),
+    });
+    return res.status;
+  }
+
+  it('blocks sign-in after deactivate and restores it after reactivate', async () => {
+    const app = createApp();
+    const adminTok = await authToken(app, 'deact-admin@example.com', 'admin');
+    // create a worker we control the password of
+    await app.request('/api/admin/users', {
+      method: 'POST',
+      headers: bearer(adminTok),
+      body: JSON.stringify({
+        email: 'deact-target@example.com',
+        name: 'Deact',
+        password: 'sterk-wachtwoord-123',
+        role: 'worker',
+      }),
+    });
+    const id = await userIdByEmail('deact-target@example.com');
+    expect(await signIn(app, 'deact-target@example.com', 'sterk-wachtwoord-123')).toBe(200);
+
+    const off = await app.request(`/api/admin/users/${id}/deactivate`, {
+      method: 'POST',
+      headers: bearer(adminTok),
+    });
+    expect(off.status).toBe(200);
+    expect((await off.json()).status).toBe('inactive');
+    expect(await signIn(app, 'deact-target@example.com', 'sterk-wachtwoord-123')).not.toBe(200);
+
+    const on = await app.request(`/api/admin/users/${id}/reactivate`, {
+      method: 'POST',
+      headers: bearer(adminTok),
+    });
+    expect((await on.json()).status).toBe('active');
+    expect(await signIn(app, 'deact-target@example.com', 'sterk-wachtwoord-123')).toBe(200);
+  });
+
+  it('refuses self-deactivation', async () => {
+    const app = createApp();
+    const adminTok = await authToken(app, 'deact-self@example.com', 'admin');
+    await authToken(app, 'deact-self-other@example.com', 'admin'); // a second admin
+    const id = await userIdByEmail('deact-self@example.com');
+    const res = await app.request(`/api/admin/users/${id}/deactivate`, {
+      method: 'POST',
+      headers: bearer(adminTok),
+    });
+    expect(res.status).toBe(400);
+    expect((await res.json()).error).toContain('deactiveren');
+  });
+
+  it('refuses deactivating the last active admin', async () => {
+    const app = createApp();
+    const adminTok = await authToken(app, 'deact-last-admin@example.com', 'admin');
+    // promote a peer, deactivate caller is self-blocked; deactivate the peer is allowed (caller remains).
+    await authToken(app, 'deact-peer@example.com', 'admin');
+    const peerId = await userIdByEmail('deact-peer@example.com');
+    const res = await app.request(`/api/admin/users/${peerId}/deactivate`, {
+      method: 'POST',
+      headers: bearer(adminTok),
+    });
+    expect(res.status).toBe(200); // caller still admin → allowed
+    // Now the peer is inactive; the caller is the only active admin. Deactivating self is blocked:
+    const callerId = await userIdByEmail('deact-last-admin@example.com');
+    const selfRes = await app.request(`/api/admin/users/${callerId}/deactivate`, {
+      method: 'POST',
+      headers: bearer(adminTok),
+    });
+    expect(selfRes.status).toBe(400); // self-guard (which also preserves the last admin)
+  });
+
+  it('404s on an unknown id and 403s for a worker', async () => {
+    const app = createApp();
+    const adminTok = await authToken(app, 'deact-404-admin@example.com', 'admin');
+    expect(
+      (
+        await app.request('/api/admin/users/nope/deactivate', {
+          method: 'POST',
+          headers: bearer(adminTok),
+        })
+      ).status,
+    ).toBe(404);
+    const workerTok = await authToken(app, 'deact-worker@example.com');
+    const id = await userIdByEmail('deact-worker@example.com');
+    expect(
+      (
+        await app.request(`/api/admin/users/${id}/deactivate`, {
+          method: 'POST',
+          headers: bearer(workerTok),
+        })
+      ).status,
+    ).toBe(403);
+  });
+});