From 8dc445b0a45f79316459af8c95600bc7666f884b Mon Sep 17 00:00:00 2001
From: Laura Beatris <48022589+LauraBeatris@users.noreply.github.com>
Date: Mon, 21 Jul 2025 15:48:24 -0300
Subject: [PATCH] Use `isSignedIn` to determine auth state

---
 .changeset/big-sides-go.md                              | 5 +++++
 packages/clerk-js/src/core/modules/checkout/instance.ts | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/big-sides-go.md

diff --git a/.changeset/big-sides-go.md b/.changeset/big-sides-go.md
new file mode 100644
index 00000000000..d8325d82f7a
--- /dev/null
+++ b/.changeset/big-sides-go.md
@@ -0,0 +1,5 @@
+---
+'@clerk/clerk-js': patch
+---
+
+Fix authentication state resolution when creating checkout instance
diff --git a/packages/clerk-js/src/core/modules/checkout/instance.ts b/packages/clerk-js/src/core/modules/checkout/instance.ts
index 7ada04d355b..223f0060e4f 100644
--- a/packages/clerk-js/src/core/modules/checkout/instance.ts
+++ b/packages/clerk-js/src/core/modules/checkout/instance.ts
@@ -24,7 +24,7 @@ function createCheckoutInstance(
 ): __experimental_CheckoutInstance {
   const { for: forOrganization, planId, planPeriod } = options;
 
-  if (!clerk.user) {
+  if (!clerk.isSignedIn || !clerk.user) {
     throw new Error('Clerk: User is not authenticated');
   }