diff --git a/packages/web/src/components/modals/settingsPanels/AccountPanel.detachedNotice.test.tsx b/packages/web/src/components/modals/settingsPanels/AccountPanel.detachedNotice.test.tsx
new file mode 100644
index 00000000..2b805993
--- /dev/null
+++ b/packages/web/src/components/modals/settingsPanels/AccountPanel.detachedNotice.test.tsx
@@ -0,0 +1,113 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen, cleanup } from '@testing-library/react';
+import type { User } from '@backspace/shared';
+
+// ── Store mocks ─────────────────────────────────────────────────────────────
+// AccountPanel reads its self user from `useAuthStore((s) => s.user)`. We drive
+// that user through a mutable fixture and mock the store with a selector-aware
+// callable (mirrors the selector-mock idiom used across the web test suite).
+let currentUser: User | null = null;
+const noop = vi.fn();
+
+interface AuthState {
+  user: User | null;
+  updateProfile: (...args: unknown[]) => unknown;
+  changePassword: (...args: unknown[]) => unknown;
+}
+
+vi.mock('../../../stores/authStore', () => ({
+  useAuthStore: Object.assign(
+    (selector: (s: AuthState) => unknown) =>
+      selector({ user: currentUser, updateProfile: noop, changePassword: noop }),
+    {
+      getState: (): AuthState => ({ user: currentUser, updateProfile: noop, changePassword: noop }),
+      setState: vi.fn(),
+      subscribe: vi.fn(),
+    },
+  ),
+}));
+
+vi.mock('../../../stores/uiStore', () => ({
+  useUIStore: Object.assign(
+    (selector: (s: { addToast: (...args: unknown[]) => void }) => unknown) =>
+      selector({ addToast: noop }),
+    { getState: () => ({ addToast: noop }), setState: vi.fn(), subscribe: vi.fn() },
+  ),
+}));
+
+vi.mock('../../../stores/instanceStore', () => ({
+  useInstanceStore: Object.assign(
+    (selector: (s: { instances: unknown[] }) => unknown) => selector({ instances: [] }),
+    { getState: () => ({ instances: [] }), setState: vi.fn(), subscribe: vi.fn() },
+  ),
+}));
+
+vi.mock('../../../stores/transferStore', () => ({
+  useTransferStore: Object.assign(
+    (selector: (s: unknown) => unknown) => selector({}),
+    { getState: () => ({ startUpload: noop, transfers: new Map() }), setState: vi.fn(), subscribe: vi.fn() },
+  ),
+}));
+
+// api.uploads.url is referenced during render for avatar/banner sources.
+vi.mock('../../../api/client', () => ({
+  api: { uploads: { url: (f: string) => `/api/uploads/${f}` } },
+}));
+
+// Child modals are closed in these render cases; stub them so their transitive
+// store imports don't participate in this isolated component render.
+vi.mock('../../ui/ImageCropModal', () => ({ ImageCropModal: () => null }));
+vi.mock('../DeleteAccountModal', () => ({ DeleteAccountModal: () => null }));
+
+import { AccountPanel } from './AccountPanel';
+
+// ── Fixtures ────────────────────────────────────────────────────────────────
+function makeUser(overrides: Partial<User> = {}): User {
+  return {
+    id: 'user-self',
+    username: 'me',
+    displayName: 'Me',
+    avatar: null,
+    banner: null,
+    accentColor: null,
+    avatarColor: null,
+    bio: null,
+    status: 'online',
+    customStatus: null,
+    isAdmin: false,
+    createdAt: 0,
+    homeInstance: null,
+    homeUserId: null,
+    replicatedInstances: [],
+    ...overrides,
+  };
+}
+
+const NOTICE = /This account is detached from its home instance\./i;
+
+beforeEach(() => {
+  cleanup();
+  currentUser = null;
+});
+
+describe('AccountPanel detached-account notice', () => {
+  it('renders the notice when the account is detached and carries a home instance', () => {
+    currentUser = makeUser({ federationHomeOrphaned: true, homeInstance: 'old.example.net' });
+    render(<AccountPanel />);
+    expect(screen.getByText(NOTICE)).toBeInTheDocument();
+    // Names the lost home instance so the owner understands what happened.
+    expect(screen.getByText(/old\.example\.net/)).toBeInTheDocument();
+  });
+
+  it('does not render the notice for a non-detached federated account', () => {
+    currentUser = makeUser({ federationHomeOrphaned: false, homeInstance: 'live.example.net' });
+    render(<AccountPanel />);
+    expect(screen.queryByText(NOTICE)).not.toBeInTheDocument();
+  });
+
+  it('does not render the notice for a normal local account (no home instance)', () => {
+    currentUser = makeUser({ federationHomeOrphaned: true, homeInstance: null });
+    render(<AccountPanel />);
+    expect(screen.queryByText(NOTICE)).not.toBeInTheDocument();
+  });
+});
diff --git a/packages/web/src/components/modals/settingsPanels/AccountPanel.tsx b/packages/web/src/components/modals/settingsPanels/AccountPanel.tsx
index ba48068b..3b838a3f 100644
--- a/packages/web/src/components/modals/settingsPanels/AccountPanel.tsx
+++ b/packages/web/src/components/modals/settingsPanels/AccountPanel.tsx
@@ -264,6 +264,13 @@ export function AccountPanel() {
   return (
     <div className="space-y-5">
       <h2 className="text-lg font-semibold text-txt-primary mb-6">My Account</h2>
+      {user?.federationHomeOrphaned && user?.homeInstance && (
+        <div className="rounded-lg bg-accent-amber/10 border border-accent-amber/25 px-3.5 py-3 text-xs text-txt-secondary leading-relaxed mb-4">
+          <span className="font-medium text-txt-primary">This account is detached from its home instance.</span>{' '}
+          {user.homeInstance} was reset or is no longer available, so this account now operates locally on
+          this instance — your profile and password are managed here.
+        </div>
+      )}
       {/* ── Profile Customization ── */}
       <div>
         <div className="text-[11px] font-semibold text-txt-tertiary uppercase tracking-wider mb-1.5">