diff --git a/.changeset/theme-access-permanent-domain.md b/.changeset/theme-access-permanent-domain.md
new file mode 100644
index 00000000000..88805df1cfa
--- /dev/null
+++ b/.changeset/theme-access-permanent-domain.md
@@ -0,0 +1,6 @@
+---
+'@shopify/cli-kit': patch
+'@shopify/theme': patch
+---
+
+Theme Access passwords now work when `--store` is a store domain other than its permanent `.myshopify.com` domain (for example a renamed `.myshopify.com` domain): the CLI looks up the permanent domain and uses it. When a Theme Access password is rejected, the error now explains how to find the permanent domain.
diff --git a/packages/cli-kit/src/private/node/session/permanent-store-domain.test.ts b/packages/cli-kit/src/private/node/session/permanent-store-domain.test.ts
new file mode 100644
index 00000000000..2045c4b9ce3
--- /dev/null
+++ b/packages/cli-kit/src/private/node/session/permanent-store-domain.test.ts
@@ -0,0 +1,144 @@
+import {clearPermanentStoreFqdnCache, resolvePermanentStoreFqdn} from './permanent-store-domain.js'
+import {fetch} from '../../../public/node/http.js'
+import {mockAndCaptureOutput} from '../../../public/node/testing/output.js'
+import {beforeEach, describe, expect, test, vi} from 'vitest'
+import {Response} from 'node-fetch'
+
+vi.mock('../../../public/node/http.js')
+
+function metaJson(body: unknown, status = 200) {
+  return new Response(JSON.stringify(body), {status, headers: {'Content-Type': 'application/json'}})
+}
+
+describe('resolvePermanentStoreFqdn', () => {
+  beforeEach(() => {
+    clearPermanentStoreFqdnCache()
+    mockAndCaptureOutput().clear()
+    vi.unstubAllEnvs()
+  })
+
+  test("returns the store's permanent domain from its public meta.json", async () => {
+    // Given
+    const outputMock = mockAndCaptureOutput()
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson({myshopify_domain: 'abc123-xy.myshopify.com'}))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('renamed-store.myshopify.com')
+
+    // Then
+    expect(got).toEqual('abc123-xy.myshopify.com')
+    expect(fetch).toHaveBeenCalledWith(
+      'https://renamed-store.myshopify.com/meta.json',
+      {headers: {Accept: 'application/json'}},
+      {useNetworkLevelRetry: false, useAbortSignal: true, timeoutMs: 5000},
+    )
+    expect(outputMock.info()).toContain(
+      'Using the permanent domain abc123-xy.myshopify.com for renamed-store.myshopify.com.',
+    )
+  })
+
+  test('returns the domain unchanged, without a message, when it already is the permanent domain', async () => {
+    // Given
+    const outputMock = mockAndCaptureOutput()
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson({myshopify_domain: 'my-store.myshopify.com'}))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('my-store.myshopify.com')
+
+    // Then
+    expect(got).toEqual('my-store.myshopify.com')
+    expect(outputMock.info()).toEqual('')
+  })
+
+  test('normalises the case of the permanent domain', async () => {
+    // Given
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson({myshopify_domain: 'My-Store.myshopify.com'}))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('alias.myshopify.com')
+
+    // Then
+    expect(got).toEqual('my-store.myshopify.com')
+  })
+
+  test('caches the result for the store and its permanent domain', async () => {
+    // Given
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson({myshopify_domain: 'abc123-xy.myshopify.com'}))
+
+    // When
+    const first = await resolvePermanentStoreFqdn('renamed-store.myshopify.com')
+    const second = await resolvePermanentStoreFqdn('renamed-store.myshopify.com')
+    const third = await resolvePermanentStoreFqdn('abc123-xy.myshopify.com')
+
+    // Then
+    expect([first, second, third]).toEqual([
+      'abc123-xy.myshopify.com',
+      'abc123-xy.myshopify.com',
+      'abc123-xy.myshopify.com',
+    ])
+    expect(fetch).toHaveBeenCalledTimes(1)
+  })
+
+  test('returns the domain unchanged when meta.json is not a success', async () => {
+    // Given
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson({errors: 'Not Found'}, 404))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('my-store.myshopify.com')
+
+    // Then
+    expect(got).toEqual('my-store.myshopify.com')
+  })
+
+  test.each([
+    ['is missing', {}],
+    ['is not a string', {myshopify_domain: 42}],
+    ['is not a store domain', {myshopify_domain: 'evil.example.com'}],
+    ['is not a .myshopify.com domain', {myshopify_domain: 'my-store.myshopify.io'}],
+    ['has more than one label before .myshopify.com', {myshopify_domain: 'evil.my-store.myshopify.com'}],
+    ['contains a path', {myshopify_domain: 'my-store.myshopify.com/admin'}],
+  ])('returns the domain unchanged when myshopify_domain %s', async (_description, body) => {
+    // Given
+    vi.mocked(fetch).mockResolvedValueOnce(metaJson(body))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('alias.myshopify.com')
+
+    // Then
+    expect(got).toEqual('alias.myshopify.com')
+  })
+
+  test('returns the domain unchanged when meta.json is not JSON', async () => {
+    // Given
+    vi.mocked(fetch).mockResolvedValueOnce(new Response('<html>Challenge</html>', {status: 200}))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('alias.myshopify.com')
+
+    // Then
+    expect(got).toEqual('alias.myshopify.com')
+  })
+
+  test('returns the domain unchanged when the request fails', async () => {
+    // Given
+    vi.mocked(fetch).mockRejectedValueOnce(new Error('The operation was aborted'))
+
+    // When
+    const got = await resolvePermanentStoreFqdn('alias.myshopify.com')
+
+    // Then
+    expect(got).toEqual('alias.myshopify.com')
+  })
+
+  test('does not look up the domain against a local development server', async () => {
+    // Given
+    vi.stubEnv('SHOPIFY_SERVICE_ENV', 'local')
+
+    // When
+    const got = await resolvePermanentStoreFqdn('my-store.shop.dev')
+
+    // Then
+    expect(got).toEqual('my-store.shop.dev')
+    expect(fetch).not.toHaveBeenCalled()
+  })
+})
diff --git a/packages/cli-kit/src/private/node/session/permanent-store-domain.ts b/packages/cli-kit/src/private/node/session/permanent-store-domain.ts
new file mode 100644
index 00000000000..a25222aaf0f
--- /dev/null
+++ b/packages/cli-kit/src/private/node/session/permanent-store-domain.ts
@@ -0,0 +1,87 @@
+import {serviceEnvironment} from '../context/service.js'
+import {extractMyshopifyHandle} from '../../../public/common/url.js'
+import {fetch} from '../../../public/node/http.js'
+import {outputContent, outputDebug, outputInfo, outputToken} from '../../../public/node/output.js'
+
+/**
+ * How long to wait for a store's public `/meta.json` before giving up and using the domain as given.
+ */
+const PERMANENT_DOMAIN_LOOKUP_TIMEOUT_MS = 5000
+
+const resolvedStoreFqdns = new Map<string, Promise<string>>()
+
+/**
+ * Resolves the permanent `.myshopify.com` domain of a store.
+ *
+ * A store can be reached through several domains (a renamed `.myshopify.com` domain, a custom domain), but some
+ * Shopify services only recognise the store's permanent domain. The Theme Access app is one of them: its passwords
+ * are tied to the permanent domain, so a request made with any other domain fails with a 401.
+ *
+ * The permanent domain is read from the store's public `/meta.json` endpoint, which needs no authentication and is
+ * served even when the storefront is password protected. When the lookup fails for any reason, the domain is
+ * returned unchanged, so callers behave exactly as they would without this lookup.
+ *
+ * Results are cached for the lifetime of the process.
+ *
+ * @param storeFqdn - The store domain the user provided, for example `my-store.myshopify.com`.
+ * @returns The store's permanent domain, or `storeFqdn` when it cannot be determined.
+ */
+export async function resolvePermanentStoreFqdn(storeFqdn: string): Promise<string> {
+  if (serviceEnvironment() === 'local') return storeFqdn
+
+  const cached = resolvedStoreFqdns.get(storeFqdn)
+  if (cached) return cached
+
+  const resolution = fetchPermanentStoreFqdn(storeFqdn)
+  resolvedStoreFqdns.set(storeFqdn, resolution)
+
+  const permanentStoreFqdn = await resolution
+  if (permanentStoreFqdn !== storeFqdn) {
+    resolvedStoreFqdns.set(permanentStoreFqdn, Promise.resolve(permanentStoreFqdn))
+    outputInfo(
+      outputContent`Using the permanent domain ${outputToken.raw(permanentStoreFqdn)} for ${outputToken.raw(
+        storeFqdn,
+      )}.`,
+    )
+  }
+  return permanentStoreFqdn
+}
+
+/**
+ * Clears the in-process cache used by {@link resolvePermanentStoreFqdn}. Intended for tests.
+ */
+export function clearPermanentStoreFqdnCache(): void {
+  resolvedStoreFqdns.clear()
+}
+
+async function fetchPermanentStoreFqdn(storeFqdn: string): Promise<string> {
+  const url = `https://${storeFqdn}/meta.json`
+  try {
+    const response = await fetch(
+      url,
+      {headers: {Accept: 'application/json'}},
+      {useNetworkLevelRetry: false, useAbortSignal: true, timeoutMs: PERMANENT_DOMAIN_LOOKUP_TIMEOUT_MS},
+    )
+    if (!response.ok) {
+      outputDebug(`Could not look up the permanent domain of ${storeFqdn}: ${url} returned HTTP ${response.status}`)
+      return storeFqdn
+    }
+
+    const body = (await response.json()) as {myshopify_domain?: unknown} | null
+    const permanentStoreFqdn = typeof body?.myshopify_domain === 'string' ? body.myshopify_domain.toLowerCase() : ''
+    // Accept only a bare `<handle>.myshopify.com`: `extractMyshopifyHandle` also accepts a URL with a path, so
+    // compare the round trip to reject anything but the domain itself.
+    const handle = extractMyshopifyHandle(permanentStoreFqdn)
+    if (!handle || `${handle}.myshopify.com` !== permanentStoreFqdn) {
+      outputDebug(`Could not look up the permanent domain of ${storeFqdn}: ${url} has no valid myshopify_domain`)
+      return storeFqdn
+    }
+
+    return permanentStoreFqdn
+    // eslint-disable-next-line no-catch-all/no-catch-all
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error)
+    outputDebug(`Could not look up the permanent domain of ${storeFqdn}: ${message}`)
+    return storeFqdn
+  }
+}
diff --git a/packages/cli-kit/src/public/node/api/admin.test.ts b/packages/cli-kit/src/public/node/api/admin.test.ts
index 976f8d2bf6a..d7b240b4323 100644
--- a/packages/cli-kit/src/public/node/api/admin.test.ts
+++ b/packages/cli-kit/src/public/node/api/admin.test.ts
@@ -310,4 +310,25 @@ describe('fetchApiVersions error classification', () => {
     expect(unauthorized).toBeInstanceOf(AbortError)
     expect((unauthorized as AbortError).message).toContain('Error connecting to your store')
   })
+
+  test('explains a rejected Theme Access password, including how to find the permanent domain', async () => {
+    // Given
+    const themeAccessSession: AdminSession = {token: 'shptka_password', storeFqdn: 'alias.myshopify.com'}
+    vi.mocked(graphqlRequestDoc).mockRejectedValue(clientError(401, 'Unauthorized'))
+
+    // When
+    const error = await admin.fetchApiVersions(themeAccessSession).catch((err: unknown) => err)
+
+    // Then
+    expect(error).toBeInstanceOf(AbortError)
+    expect(shouldReportErrorAsUnexpected(error)).toBe(false)
+    expect((error as AbortError).message).toBe(
+      'The Theme Access password was rejected for the store alias.myshopify.com.',
+    )
+    expect(String((error as AbortError).tryMessage)).toContain('permanent .myshopify.com domain')
+    const nextSteps = JSON.stringify((error as AbortError).nextSteps)
+    expect(nextSteps).toContain('Settings > Domains')
+    // The domain the user passed may not be a real store, so the error must not send them to a URL built from it.
+    expect(nextSteps).not.toContain('alias.myshopify.com')
+  })
 })
diff --git a/packages/cli-kit/src/public/node/api/admin.ts b/packages/cli-kit/src/public/node/api/admin.ts
index c70ad55e1f8..7ed3eda69a8 100644
--- a/packages/cli-kit/src/public/node/api/admin.ts
+++ b/packages/cli-kit/src/public/node/api/admin.ts
@@ -186,6 +186,23 @@ export async function fetchApiVersions(
         outputContent`If you're not the owner, create a dev store staff account for yourself`,
       )
     }
+    if (error instanceof ClientError && error.response.status === 401 && isThemeAccessSession(session)) {
+      throw new AbortError(
+        `The Theme Access password was rejected for the store ${session.storeFqdn}.`,
+        'Theme Access passwords only work on the store they were generated for, and only with its permanent .myshopify.com domain.',
+        [
+          'Check that the password was created in the Theme Access app on this store and has not been deleted.',
+          [
+            'Pass the permanent domain to',
+            {command: '--store'},
+            {char: '.'},
+            'It is the .myshopify.com domain listed in the Shopify admin under',
+            {subdued: 'Settings > Domains'},
+            {char: '.'},
+          ],
+        ],
+      )
+    }
     if (error instanceof ClientError && (error.response.status === 401 || error.response.status === 404)) {
       throw new AbortError(
         `Error connecting to your store ${session.storeFqdn}: ${error.message} ${error.response.status} ${error.response.data}`,
diff --git a/packages/cli-kit/src/public/node/session.test.ts b/packages/cli-kit/src/public/node/session.test.ts
index a0785a5a578..0d7774807fe 100644
--- a/packages/cli-kit/src/public/node/session.test.ts
+++ b/packages/cli-kit/src/public/node/session.test.ts
@@ -29,6 +29,7 @@ import {
   exchangeAppAutomationTokenForAppManagementAccessToken,
   exchangeAppAutomationTokenForBusinessPlatformAccessToken,
 } from '../../private/node/session/exchange.js'
+import {resolvePermanentStoreFqdn} from '../../private/node/session/permanent-store-domain.js'
 
 import {vi, describe, expect, test} from 'vitest'
 
@@ -44,6 +45,7 @@ vi.mock('../../private/node/session.js')
 vi.mock('../../private/node/session/exchange.js')
 vi.mock('../../private/node/session/store.js')
 vi.mock('../../private/node/session/automation-token.js')
+vi.mock('../../private/node/session/permanent-store-domain.js')
 vi.mock('./environment.js')
 vi.mock('./http.js')
 
@@ -284,9 +286,13 @@ describe('ensureAuthenticatedTheme', () => {
     expect(got).toEqual({token: 'password', storeFqdn: 'mystore.myshopify.com'})
     expect(setLastSeenAuthMethod).toBeCalledWith('custom_app_token')
     expect(setLastSeenUserIdAfterAuth).toBeCalledWith(nonRandomUUID('password'))
+    expect(resolvePermanentStoreFqdn).not.toHaveBeenCalled()
   })
 
   test('returns the password when is provided and theme_access_token', async () => {
+    // Given
+    vi.mocked(resolvePermanentStoreFqdn).mockImplementation(async (store) => store)
+
     // When
     const got = await ensureAuthenticatedThemes('mystore.myshopify.com', 'shptka_password')
 
@@ -295,6 +301,18 @@ describe('ensureAuthenticatedTheme', () => {
     expect(setLastSeenAuthMethod).toBeCalledWith('theme_access_token')
     expect(setLastSeenUserIdAfterAuth).toBeCalledWith(nonRandomUUID('shptka_password'))
   })
+
+  test("uses the store's permanent domain with a theme_access_token", async () => {
+    // Given
+    vi.mocked(resolvePermanentStoreFqdn).mockResolvedValueOnce('abc123-xy.myshopify.com')
+
+    // When
+    const got = await ensureAuthenticatedThemes('renamed-store.myshopify.com', 'shptka_password')
+
+    // Then
+    expect(resolvePermanentStoreFqdn).toHaveBeenCalledWith('renamed-store.myshopify.com')
+    expect(got).toEqual({token: 'shptka_password', storeFqdn: 'abc123-xy.myshopify.com'})
+  })
 })
 
 describe('ensureAuthenticatedBusinessPlatform', () => {
diff --git a/packages/cli-kit/src/public/node/session.ts b/packages/cli-kit/src/public/node/session.ts
index 659f9aa89d6..008effd3777 100644
--- a/packages/cli-kit/src/public/node/session.ts
+++ b/packages/cli-kit/src/public/node/session.ts
@@ -24,6 +24,7 @@ import {
   setLastSeenUserIdAfterAuth,
 } from '../../private/node/session.js'
 import {isThemeAccessSession} from '../../private/node/api/rest.js'
+import {resolvePermanentStoreFqdn} from '../../private/node/session/permanent-store-domain.js'
 
 /**
  * Session Object to access the Admin API, includes the token and the store FQDN.
@@ -275,6 +276,10 @@ ${outputToken.json(scopes)}
  * If a password is provided, that token will be used against Theme Access API.
  * Otherwise, it will ensure that the user is authenticated with the Admin API.
  *
+ * Theme Access passwords only work with the store's permanent `.myshopify.com` domain, so when the password is a
+ * Theme Access password the returned session uses the permanent domain of `store`, even if `store` is another of the
+ * store's domains.
+ *
  * @param store - Store fqdn to request auth for.
  * @param password - Password generated from Theme Access app.
  * @param scopes - Optional array of extra scopes to authenticate with.
@@ -292,9 +297,10 @@ ${outputToken.json(scopes)}
 `)
   if (password) {
     const session = {token: password, storeFqdn: store}
-    const authMethod = isThemeAccessSession(session) ? 'theme_access_token' : 'custom_app_token'
-    setLastSeenAuthMethod(authMethod)
+    const themeAccess = isThemeAccessSession(session)
+    setLastSeenAuthMethod(themeAccess ? 'theme_access_token' : 'custom_app_token')
     setLastSeenUserIdAfterAuth(nonRandomUUID(password))
+    if (themeAccess) session.storeFqdn = await resolvePermanentStoreFqdn(store)
     return session
   }
   return ensureAuthenticatedAdmin(store, scopes, options)