@@ -521,8 +521,8 @@ export function Billing({ scope, organizationId, creditUsageHref }: BillingProps
           </div>
         </div>
         {!subscription.isEnterprise &&
+          marketplaceBilling.isResolved &&
           !billedThroughMarketplace &&
-          !marketplaceBilling.isPending &&
           (canExplorePlans && upgradeHref ? (
             <ChipLink
               href={upgradeHref}
 
@@ -40,6 +40,10 @@ export interface UpgradeState {
   }
   showUpgradePlans: boolean
   billedThroughMarketplace: boolean
+  /** How this workspace is billed could not be read, so plans stay hidden until a retry succeeds. */
+  billingLookupFailed: boolean
+  isRetryingBillingLookup: boolean
+  retryBillingLookup: () => void
   proTier: { credits: number; dollars: number; name: string }
   maxTier: { credits: number; dollars: number; name: string }
   isOnPro: boolean
@@ -201,8 +205,11 @@ export function useUpgradeState({
     setIsAnnual,
     subscription,
     showUpgradePlans:
-      !subscription.isEnterprise && !marketplace.isPending && !marketplace.billedThroughMarketplace,
+      !subscription.isEnterprise && marketplace.isResolved && !marketplace.billedThroughMarketplace,
     billedThroughMarketplace: marketplace.billedThroughMarketplace,
+    billingLookupFailed: !marketplace.isResolved && marketplace.isError,
+    isRetryingBillingLookup: marketplace.isRetrying,
+    retryBillingLookup: marketplace.retry,
     proTier: PRO_TIER,
     maxTier: MAX_TIER,
     isOnPro,
 
@@ -85,12 +85,15 @@ export function Upgrade({ workspaceId }: UpgradeProps) {
     return null
   }
 
-  if (!canManageBilling || state.billedThroughMarketplace) {
-    const description = canManageBilling
-      ? 'Your subscription is billed through AWS Marketplace, so plans can’t be changed here.'
-      : hostContext.hostOrganizationId
+  if (!canManageBilling || state.billedThroughMarketplace || state.billingLookupFailed) {
+    const description = !canManageBilling
+      ? hostContext.hostOrganizationId
         ? `Plans for ${hostContext.workspace.name} are managed by its organization administrators. Contact an organization admin to change this workspace’s plan.`
         : `Only the owner of ${hostContext.workspace.name} can change this workspace’s plan.`
+      : state.billedThroughMarketplace
+        ? 'Your subscription is billed through AWS Marketplace, so plans can’t be changed here.'
+        : 'We couldn’t confirm how this workspace is billed.'
+    const canRetryLookup = canManageBilling && state.billingLookupFailed
 
     return (
       <div className='flex h-full flex-col bg-[var(--bg)]'>
@@ -103,6 +106,15 @@ export function Upgrade({ workspaceId }: UpgradeProps) {
           <div className='flex max-w-md flex-col items-center gap-3 text-center'>
             <h1 className='text-[var(--text-body)] text-lg'>Workspace plans unavailable</h1>
             <p className='text-[var(--text-muted)] text-sm'>{description}</p>
+            {canRetryLookup && (
+              <Chip
+                variant='border'
+                disabled={state.isRetryingBillingLookup}
+                onClick={state.retryBillingLookup}
+              >
+                {state.isRetryingBillingLookup ? 'Retrying…' : 'Try again'}
+              </Chip>
+            )}
           </div>
         </div>
       </div>
 
@@ -0,0 +1,74 @@
+/** @vitest-environment jsdom */
+
+import { act } from 'react'
+import {
+  apiClientRequestMock,
+  apiClientRequestMockFns,
+} from '@sim/testing/mocks/api-client-request.mock'
+import { authClientMock } from '@sim/testing/mocks/auth-client.mock'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { createRoot, type Root } from 'react-dom/client'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+
+vi.mock('@/lib/api/client/request', () => apiClientRequestMock)
+vi.mock('@/lib/auth/client', () => authClientMock)
+
+import { useAwsMarketplaceBilling } from '@/hooks/queries/aws-marketplace'
+
+const mockRequestJson = apiClientRequestMockFns.mockRequestJson
+
+let root: Root | null = null
+let billing: ReturnType<typeof useAwsMarketplaceBilling> | undefined
+
+function Probe() {
+  billing = useAwsMarketplaceBilling('org-1')
+  return null
+}
+
+function render() {
+  ;(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  const container = document.createElement('div')
+  document.body.appendChild(container)
+  root = createRoot(container)
+  act(() => {
+    root?.render(
+      <QueryClientProvider client={queryClient}>
+        <Probe />
+      </QueryClientProvider>
+    )
+  })
+}
+
+async function settled(assertion: () => void) {
+  await act(async () => {
+    await vi.waitFor(assertion, { interval: 1, timeout: 2_000 })
+  })
+}
+
+afterEach(() => {
+  act(() => root?.unmount())
+  root = null
+  billing = undefined
+  document.body.replaceChildren()
+})
+
+describe('useAwsMarketplaceBilling', () => {
+  it('stays unresolved when the license lookup fails, so plan changes stay gated', async () => {
+    mockRequestJson.mockRejectedValueOnce(new Error('lookup failed'))
+    render()
+
+    await settled(() => expect(billing?.isError).toBe(true))
+    expect(billing?.isResolved).toBe(false)
+    expect(billing?.billedThroughMarketplace).toBe(false)
+  })
+
+  it('resolves to not Marketplace-billed when the scope holds no license', async () => {
+    mockRequestJson.mockResolvedValueOnce({ licenses: [] })
+    render()
+
+    await settled(() => expect(billing?.isResolved).toBe(true))
+    expect(billing?.billedThroughMarketplace).toBe(false)
+    expect(billing?.isError).toBe(false)
+  })
+})
@@ -1,3 +1,4 @@
+import { useCallback } from 'react'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { requestJson } from '@/lib/api/client/request'
 import type { ContractBodyInput } from '@/lib/api/contracts'
@@ -70,12 +71,21 @@ export function useSaveAwsMarketplaceClaimContact() {
 
 /**
  * Whether AWS Marketplace bills this scope: the organization, or with null the viewer's account.
- * A failed read reports false, so a lookup error never blocks a customer who pays through Stripe.
+ * Until `isResolved`, how the scope is billed is unknown, and an unknown state gates plan changes
+ * the same as Marketplace billing does: a failed lookup must not open Stripe checkout to a
+ * customer AWS bills. `retry` reads it again.
  */
 export function useAwsMarketplaceBilling(organizationId: string | null) {
   const licenses = useAwsMarketplaceLicenses(organizationId)
+  const { refetch } = licenses
+  const retry = useCallback(() => {
+    void refetch()
+  }, [refetch])
   return {
-    isPending: licenses.isPending,
+    isResolved: licenses.data !== undefined,
+    isError: licenses.isError,
+    isRetrying: licenses.isFetching,
+    retry,
     billedThroughMarketplace:
       licenses.data?.some((license) => license.status !== 'inactive') ?? false,
   }
 
@@ -3,6 +3,8 @@ import { subscription } from '@sim/db/schema'
 import { createLogger } from '@sim/logger'
 import { APIError } from 'better-auth/api'
 import { and, eq, isNotNull } from 'drizzle-orm'
+import { getAwsMarketplaceProductCode } from '@/lib/billing/aws-marketplace/config'
+import { holdsMarketplaceLicense } from '@/lib/billing/aws-marketplace/repository'
 import { isOrganizationOwnerOrAdmin } from '@/lib/billing/core/organization'
 import {
   getOrganizationCoverageForMember,
@@ -55,6 +57,22 @@ async function assertNoBoundIncompleteSubscription(referenceId: string): Promise
   })
 }
 
+/**
+ * Refuse a Stripe checkout for a reference AWS Marketplace bills. A listed product must be billed
+ * entirely through AWS, and such a customer looks Free to Stripe, so a checkout would start a
+ * second, real subscription. The client hides plans too, but only this check holds when its
+ * license lookup fails.
+ */
+async function assertNotBilledThroughMarketplace(referenceId: string): Promise<void> {
+  if (!getAwsMarketplaceProductCode()) return
+  if (!(await holdsMarketplaceLicense(referenceId))) return
+
+  logger.warn('Blocking checkout - reference is billed through AWS Marketplace', { referenceId })
+  throw new APIError('CONFLICT', {
+    message: 'This subscription is billed through AWS Marketplace. Contact support to change it.',
+  })
+}
+
 /**
  * Classify a `/subscription/upgrade` request as a personal checkout using
  * the same reference resolution as the Better Auth Stripe plugin
@@ -81,9 +99,10 @@ export function isPersonalCheckoutRequest(
 /**
  * Guard for personal (user-referenced) checkouts on `/subscription/upgrade`.
  *
- * Blocks both a bound, incomplete Stripe subscription and a member already
- * covered by an entitled organization subscription. Throws {@link APIError}
- * with a user-facing message; the checkout UI surfaces it as-is.
+ * Blocks an account AWS Marketplace bills, a bound, incomplete Stripe
+ * subscription, and a member already covered by an entitled organization
+ * subscription. Throws {@link APIError} with a user-facing message; the
+ * checkout UI surfaces it as-is.
  *
  * Called from the Better Auth `hooks.before` middleware, NOT from
  * `authorizeReference`: the Stripe plugin skips `authorizeReference`
@@ -94,6 +113,7 @@ export function isPersonalCheckoutRequest(
  * rejected rather than risking a duplicate subscription.
  */
 export async function assertPersonalCheckoutAllowed(userId: string): Promise<void> {
+  await assertNotBilledThroughMarketplace(userId)
   await assertNoBoundIncompleteSubscription(userId)
 
   const coverage = await getOrganizationCoverageForMember(userId)
@@ -130,6 +150,7 @@ export async function assertPersonalCheckoutAllowed(userId: string): Promise<voi
  * For `upgrade-subscription` (checkout) this enforces, each thrown as an
  * {@link APIError} with a descriptive message so callers see the real
  * reason instead of a generic "Unauthorized":
+ * - An organization AWS Marketplace bills cannot check out through Stripe.
  * - Organizations can only check out Team or Enterprise plans — a `pro_*`
  *   plan can never become org-referenced.
  * - A bound, incomplete Stripe subscription must finish before another
@@ -148,6 +169,10 @@ export async function authorizeSubscriptionReference(
     return true
   }
 
+  if (action === 'upgrade-subscription') {
+    await assertNotBilledThroughMarketplace(referenceId)
+  }
+
   if (action === 'upgrade-subscription' && !isOrgPlan(plan)) {
     logger.warn('Blocking checkout - organizations can only subscribe to Team or Enterprise', {
       userId,