Problem-Solution Page
Customers Can Pay. Access, Webhooks and Subscriptions May Not Work.
Stripe received the money. The product did not update the plan. This is the most common silent failure in AI-built SaaS. The checkout looks fine. The confirmation email sends. But the user's account stays on the free tier.
Who This Is For
This Page Is For You If You Recognise This.
Situation 1
You connected Stripe but never tested failure cases
You tested a successful payment once. You never tested a failed card, a refund, a subscription cancellation, or a webhook arriving 30 seconds late.
Situation 2
You used an AI tool or template to set up billing
The AI builder wired up the Stripe integration. It looks complete. But webhook endpoint registration, signature verification, and idempotency handling may not be set up.
Situation 3
You cannot describe exactly what happens after payment
Stripe charges the card. Then what? Who updates the user's plan? What triggers it? What happens if that step fails? If you cannot answer these in one minute, the flow is not fully defined.
Pre-Launch Self-Check
7 Things to Verify Before the First Real Charge
Webhook endpoint is registered and receiving events
In Stripe Dashboard, go to Developers → Webhooks. Check that your endpoint URL is listed, active, and has received events in the last 7 days. Check the event types registered include checkout.session.completed, customer.subscription.updated, and invoice.payment_failed.
Webhook signature verification is turned on
Open the code that handles incoming webhooks. Check it calls stripe.webhooks.constructEvent() with the Stripe-Signature header and your webhook signing secret. If it does not, any server can send fake payment events to your endpoint.
Paid access updates from the webhook, not the redirect
Test this: open a second browser tab on a slow connection. Complete a test payment. Close the redirect page before it loads. Check whether the user's account got upgraded. If it did not, your plan update depends on the success page redirect and will break on slow or cancelled connections.
Failed payment removes or suspends access
In Stripe test mode, use a card that fails on the second charge (card number 4000 0000 0000 0341). Check whether the user's account goes back to the free tier or shows a payment-required message. If it stays active, paying users who cancel or whose card fails stay on paid access.
Subscription cancellation removes access on the correct date
Cancel a test subscription. Check whether access continues until the end of the billing period or stops immediately. Neither is wrong, but your terms of service must match what the code does. Also check that a cancelled subscription cannot be reactivated by replaying a webhook.
Admin can manually fix a user's plan without developer access
Log into your admin panel. Find a test user. Change their plan from free to paid manually. Change it back. If you cannot do this without touching the database directly or asking a developer, your first real payment edge case will require developer time to fix.
Webhook failures are logged and retried
In Stripe, webhooks retry automatically on failure, but your endpoint must return a 200 response. Check your server logs for webhook events. If a webhook fails and is retried, does your code process it twice? Idempotency (checking whether an event was already processed) prevents double upgrades or double charges.
Diagnosis
What You See and What It Usually Means
| What you see | What it usually means | What to do next |
|---|---|---|
| Payment succeeds but plan does not upgrade | Webhook not received or not processing the correct event type | Check webhook dashboard, verify event types registered, add logging to handler |
| User pays but gets an error page | Checkout session completed but redirect URL fails or access check runs before webhook lands | Decouple plan upgrade from redirect. Upgrade on webhook, not on page load |
| Cancelled user still has paid access | Cancellation event not handled or subscription status not checked on each request | Add subscription status check on every protected route, handle customer.subscription.deleted |
| Duplicate charges on some accounts | Webhook retry processed twice without idempotency check | Store processed event IDs and skip events already handled |
| Refund issued but user keeps access | Refund event not handled in webhook handler | Add charge.refunded or payment_intent.refunded handler that downgrades the account |
FAQ
Questions Founders Ask Before Charging Users
Is Stripe test mode enough to catch these issues?
For most cases, yes. Stripe test mode has specific card numbers for declined cards, failed renewals, and 3D Secure flows. Use them all, not just the happy path card.
What if we are using a different payment provider?
The same logic applies to Paddle, LemonSqueezy, Chargebee, or any provider with webhooks. The checks are the same: webhook registration, signature verification, access update source, and failure handling.
Does our payment provider handle all of this automatically?
No. The provider handles the charge. You handle what your product does in response. That logic lives in your code and must be tested explicitly.
How long does a payment audit take?
For a standard Stripe integration with 1 product and 1 plan type, a focused audit takes 1 to 2 days. More plan types, more providers, or more complex access rules add time.
Should I do this before or after launch?
Before. A payment failure on launch day creates a manual support problem and erodes trust. The 7 checks in this page can be run in under 4 hours by any developer familiar with the codebase.
What if we cannot fix everything before launch?
Prioritise in this order: webhook verification first, paid access source second, failed payment handling third. The others can follow, but those 3 protect money and trust.
Related Problems
Other Problems Founders Check Around This
Technical Audit
Payment is where users decide if they trust your product.
If the self-check found open questions on webhooks, access control, or failure handling, the payment flow needs a full review before real charges go through.
Start With a Technical Audit