diff --git a/api/src/services/customers/customers.ts b/api/src/services/customers/customers.ts
index 339a965..8bfe344 100644
--- a/api/src/services/customers/customers.ts
+++ b/api/src/services/customers/customers.ts
@@ -26,7 +26,7 @@ export const retrieveStripeCustomer = async ({
 }: QueryRetrieveStripeCustomerArgs): Promise<ParsedStripeResponse<Stripe.Customer | Stripe.DeletedCustomer>> => {
   const { id, addProps } = data ?? {};
 
-  if (id !== null) {
+  if (id == null) {
     throw nonNilAssertionError("retrieveStripeCustomer:id", data);
   }