Stripe Billing Audit: will your app actually get paid?
Every audit service will tell you whether your app is secure. Almost nobody checks whether your billing works: whether the Stripe integration your AI tool wrote will actually collect money, revoke access when someone cancels, and recover when a card fails. That's the audit I built, because I've run production Stripe billing on my own apps with my own revenue on the line.
Billing bugs are worse than security bugs in one specific way: they're silent. A breach announces itself eventually. A subscription that never gets revoked, a webhook that anyone can fake, a dunning flow that doesn't exist. Those just quietly cost you money every month, and nothing ever looks wrong.
- Fixed price
- No sales call
- Report in days
- Written for founders, not engineers
The billing bugs AI-built apps ship with
Webhooks with no signature verification.
If your endpoint doesn't verify Stripe's signature, anyone who finds the URL can POST a fake “payment succeeded” event and get your product for free. This is a one-line fix that generated code routinely omits, and it's a Critical finding every time.
The canceled-user bug.
The single most common revenue bug in vibe-coded apps: the happy path (checkout) is handled, the sad path (customer.subscription.deleted) is not. Users cancel, their card stops being charged, and they keep full access forever. You don't lose the user, you lose the revenue and keep the costs.
Failed payments that fail silently.
Cards expire and payments bounce constantly; it's a fact of subscription life. If invoice.payment_failed isn't handled and Stripe's retries and recovery emails aren't configured, that recoverable revenue just evaporates. Turning dunning on is close to free money, and most founders never do it.
Price tampering at checkout.
If price IDs or amounts are assembled client-side, a user can check out at a price you didn't set. Prices belong on the server, full stop.
Test keys in production.
It sounds absurd, but it happens: apps “launched” with test-mode Stripe keys, meaning no real card has ever been charged. Everything looks perfect (the checkout flows, the success screens) and revenue is exactly zero.
Replayed events double-provisioning.
Stripe redelivers webhook events. Without idempotency handling, a redelivered event can double-credit an account or extend a subscription twice.
What the billing audit actually tests
This is the flagship section of my Launch + Revenue Audit. With a restricted read-only Stripe key and test accounts, I walk your billing through its whole life cycle:
Webhook wiring, end to end.
Signature verification present, idempotency handled, and all four lifecycle events covered: checkout completed, payment failed, subscription updated, subscription deleted.
The canceled-user test.
I cancel a test subscription and watch what happens. Does access revoke? When: immediately, at period end, never? Does the user get told?
The failed-payment test.
I simulate a failed invoice. What happens to access, are Smart Retries and recovery emails configured, and does anyone (you or the user) find out?
Price and mode integrity.
Price IDs referenced server-side, live vs test keys correct in production, currency and tax settings sane.
Trials, upgrades, downgrades, refunds.
Trial expiry actually converts or cuts off, proration behaves intentionally, refunds revoke access, and the customer portal is on so users can self-manage instead of filing chargebacks.
Why this audit is rare
Security firms audit security; it's what their tooling and training cover. Billing correctness lives in an awkward gap: it's not a vulnerability, so scanners ignore it; it's product logic, so pentesters skip it; and it requires having actually operated subscription billing to know where it breaks. I check it because I've been the person whose own revenue depended on these webhooks firing correctly.
The report treats revenue findings exactly like security findings: severity, plain-English business impact, a fix prompt for your AI tool, and a verify step. RevenueCat apps get the same treatment: entitlements checked server-side, webhook sync, sandbox vs production receipts.
What it costs
Billing correctness is the heart of the Launch + Revenue Audit. The security-only tiers are here too if that's where you are today:
| Package | Price | Turnaround | Best for |
|---|---|---|---|
| Launch Scan | $299 | 48-hour turnaround | “I just want to know if anything is on fire.” |
| Launch Audit | $999 | 5 business days | “Real users are about to trust me with their data.” |
| Launch + Revenue AuditMost popular | $1,900 | 5-7 business days | “This app is supposed to make money. Prove the pipes are connected.” |
| Ship Monitor | $149/month | Ongoing | everyone who just passed an audit and plans to keep building. |
Frequently asked questions
How is this different from a security audit?
A security audit asks 'can someone take something they shouldn't?' A billing audit asks 'will you receive what you're owed?' Both are launch-blocking questions, and the second one is checked far less often. The Launch + Revenue Audit does both in one engagement.
What access do you need to my Stripe account?
A restricted, read-only API key (never your full secret key) or a screen recording of the relevant dashboard settings. Testing happens on test-mode subscriptions and test accounts. I never take write access, and access is deleted 30 days after the engagement.
My app uses RevenueCat, not Stripe directly. Does this apply?
Yes, and mobile billing is where my own scar tissue is thickest. I check that entitlements are verified server-side, that RevenueCat webhooks sync subscription state to your backend, and that sandbox and production receipts are handled separately.
Can you just tell me if my canceled users lose access?
That single question is answered in every Launch + Revenue Audit; it's the first thing I test. There isn't a smaller product for it yet, but the free scan will tell you whether your billing setup looks risky enough to be worth the full check.