diff --git a/.changeset/protect-check-standalone-signup.md b/.changeset/protect-check-standalone-signup.md
new file mode 100644
index 00000000000..a056f4268ee
--- /dev/null
+++ b/.changeset/protect-check-standalone-signup.md
@@ -0,0 +1,5 @@
+---
+'@clerk/ui': patch
+---
+
+Fix standalone `<SignUp />` Protect checks so the verification card stays mounted while a solved challenge routes to the next step, while stale direct visits to the protect-check route return to the start of the sign-up flow.
diff --git a/packages/ui/src/components/SignUp/SignUpProtectCheck.tsx b/packages/ui/src/components/SignUp/SignUpProtectCheck.tsx
index 67b9f5615e7..9e1fe542a9b 100644
--- a/packages/ui/src/components/SignUp/SignUpProtectCheck.tsx
+++ b/packages/ui/src/components/SignUp/SignUpProtectCheck.tsx
@@ -1,6 +1,6 @@
 import { useClerk } from '@clerk/shared/react';
 import type { SignUpProps, SignUpResource } from '@clerk/shared/types';
-import type { ComponentType } from 'react';
+import { type ComponentType, useEffect, useRef, useState } from 'react';
 
 import { Card } from '@/ui/elements/Card';
 import { useCardState, withCardStateProvider } from '@/ui/elements/contexts';
@@ -19,6 +19,7 @@ import {
   Spinner,
   useLocalizations,
 } from '../../customizables';
+import { useNavigateToFlowStart } from '../../hooks/useNavigateToFlowStart';
 import { useProtectCheckRunner } from '../../hooks/useProtectCheckRunner';
 import { useRouter } from '../../router';
 import { completeSignUpFlow } from './util';
@@ -42,13 +43,31 @@ function SignUpProtectCheckInternal({
   verifyPhonePath = '../verify-phone-number',
   continuePath = '../continue',
   protectCheckPath = '.',
-}: SignUpProtectCheckProps = {}): JSX.Element {
+}: SignUpProtectCheckProps = {}): JSX.Element | null {
   const card = useCardState();
   const { t } = useLocalizations();
   const signUp = useCoreSignUp();
   const { navigate } = useRouter();
+  const { navigateToFlowStart } = useNavigateToFlowStart();
   const { setActive } = useClerk();
   const { afterSignUpUrl, navigateOnSetActive } = useSignUpContext();
+  // Latches that a protect check existed at some point, so the resolution race
+  // (submitProtectCheck clearing protectCheck mid-navigation) isn't mistaken for
+  // a stale visit. State adjusted during render (guarded) rather than a ref
+  // write, which React disallows in the render body.
+  const [everSawProtectCheck, setEverSawProtectCheck] = useState(!!signUp.protectCheck);
+  const didStartNoCheckFallbackRef = useRef(false);
+
+  if (signUp.protectCheck && !everSawProtectCheck) {
+    setEverSawProtectCheck(true);
+  }
+
+  useEffect(() => {
+    if (!signUp.protectCheck && !everSawProtectCheck && !didStartNoCheckFallbackRef.current) {
+      didStartNoCheckFallbackRef.current = true;
+      void navigateToFlowStart();
+    }
+  }, [everSawProtectCheck, navigateToFlowStart, signUp.protectCheck]);
 
   const { containerRef, isRunning, hasError, retry } = useProtectCheckRunner<SignUpResource>({
     getProtectCheck: () => signUp.protectCheck,
@@ -81,6 +100,13 @@ function SignUpProtectCheckInternal({
     },
   });
 
+  // Stale/direct visit that never had a check: render nothing while the
+  // flow-start redirect scheduled above kicks in, instead of flashing the card
+  // shell for one paint. Must stay below every hook call.
+  if (!signUp.protectCheck && !everSawProtectCheck) {
+    return null;
+  }
+
   return (
     <Flow.Part part='protectCheck'>
       <Card.Root>
diff --git a/packages/ui/src/components/SignUp/__tests__/SignUpProtectCheck.test.tsx b/packages/ui/src/components/SignUp/__tests__/SignUpProtectCheck.test.tsx
index cd0f9196935..a32a29b717d 100644
--- a/packages/ui/src/components/SignUp/__tests__/SignUpProtectCheck.test.tsx
+++ b/packages/ui/src/components/SignUp/__tests__/SignUpProtectCheck.test.tsx
@@ -6,6 +6,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { bindCreateFixtures } from '@/test/create-fixtures';
 import { fireEvent, render } from '@/test/utils';
 
+import { SignUp } from '../index';
 import { SignUpProtectCheck } from '../SignUpProtectCheck';
 
 vi.mock('@clerk/shared/internal/clerk-js/protectCheck', () => ({
@@ -34,6 +35,46 @@ describe('SignUpProtectCheck', () => {
     expect(await findByText(/verifying your request/i)).toBeInTheDocument();
   });
 
+  it('keeps the standalone protect-check route mounted after protectCheck clears', async () => {
+    const { wrapper, fixtures } = await createFixtures(f => {
+      f.startSignUpWithProtectCheck();
+    });
+    fixtures.router.currentPath = '/sign-up/protect-check';
+    fixtures.router.fullPath = '/sign-up';
+    fixtures.router.indexPath = '/sign-up';
+    fixtures.router.matches.mockImplementation((path?: string) => path === 'protect-check');
+    mockExecute.mockReturnValue(new Promise(() => {}));
+
+    const { findByText, queryByText, rerender } = render(<SignUp />, { wrapper });
+
+    expect(await findByText(/verifying your request/i)).toBeInTheDocument();
+
+    (fixtures.signUp as any).protectCheck = null;
+    (fixtures.signUp as any).missingFields = [];
+    rerender(<SignUp />);
+
+    expect(queryByText(/verifying your request/i)).toBeInTheDocument();
+    expect(fixtures.router.navigate).not.toHaveBeenCalledWith('/sign-up');
+  });
+
+  it('routes stale standalone protect-check visits back to the flow start', async () => {
+    const { wrapper, fixtures } = await createFixtures(f => {
+      f.startSignUpWithEmailAddress();
+    });
+    fixtures.router.currentPath = '/sign-up/protect-check';
+    fixtures.router.fullPath = '/sign-up';
+    fixtures.router.indexPath = '/sign-up';
+
+    const { queryByText } = render(<SignUpProtectCheck />, { wrapper });
+
+    // The card shell must not flash while the redirect below kicks in.
+    expect(queryByText(/verifying your request/i)).not.toBeInTheDocument();
+
+    await waitFor(() => expect(fixtures.router.navigate).toHaveBeenCalledWith('/sign-up'));
+    expect(mockExecute).not.toHaveBeenCalled();
+    expect(queryByText(/verifying your request/i)).not.toBeInTheDocument();
+  });
+
   it('runs the SDK challenge with the URL and resource and submits the proof token', async () => {
     const { wrapper, fixtures } = await createFixtures(f => {
       f.startSignUpWithProtectCheck({ sdkUrl: 'https://protect.example.com/v1.js' });
diff --git a/packages/ui/src/components/SignUp/index.tsx b/packages/ui/src/components/SignUp/index.tsx
index 598dfc6c2d6..a6c72b24b2c 100644
--- a/packages/ui/src/components/SignUp/index.tsx
+++ b/packages/ui/src/components/SignUp/index.tsx
@@ -35,10 +35,11 @@ function SignUpRoutes(): JSX.Element {
   return (
     <Flow.Root flow='signUp'>
       <Switch>
-        <Route
-          path='protect-check'
-          canActivate={clerk => !!clerk.client.signUp.protectCheck}
-        >
+        {/* No canActivate guard here. `!!signUp.protectCheck` flips to false
+            when submitProtectCheck resolves and clears protectCheck, which
+            unmounts this card mid-navigation and blanks the route. The card
+            owns its own post-resolution routing. */}
+        <Route path='protect-check'>
           <SignUpProtectCheck />
         </Route>
         <Route
@@ -75,10 +76,9 @@ function SignUpRoutes(): JSX.Element {
           />
         </Route>
         <Route path='continue'>
-          <Route
-            path='protect-check'
-            canActivate={clerk => !!clerk.client.signUp.protectCheck}
-          >
+          {/* No canActivate guard: same resolution race as the top-level
+              protect-check route; the card owns its own routing. */}
+          <Route path='protect-check'>
             {/* Under `continue`, the continue index is `..`, not `../continue`. */}
             <SignUpProtectCheck continuePath='..' />
           </Route>