Penetration testing for fintech
In most products a logic flaw leaks data. In fintech it moves money, whether through two requests sent at the same moment or a negative amount nobody thought to block. We test payments, ledgers, onboarding and APIs for the mistakes that turn into losses.
What we test in a fintech product
Automated scanners do not understand money. Most of a fintech engagement is manual testing of how value moves through your system and who is allowed to move it.
| Area | What we try to break |
|---|---|
| Money movement | Race conditions that spend a balance twice, negative and fractional amounts, rounding and currency conversion errors, and replayed or reordered transactions. |
| Ledgers and balances | Whether balances, limits and fees are calculated and enforced on the server, and whether one account can read or affect another's. |
| Onboarding and KYC | Skipping verification steps, reusing or tampering with uploaded documents, and reaching features before checks are complete. |
| Authentication | OTP and MFA bypass, device binding, session handling, password reset and account recovery, which attackers use for account takeover. |
| APIs and partners | Your public and partner APIs, payment provider callbacks and webhook signature checks, tested against the OWASP API Security Top 10. |
| Mobile apps | Local storage, certificate pinning and tampering protections on iOS and Android, against OWASP MASVS. |
The rules that ask for testing
Card data brings PCI DSS, which requires penetration tests at least once a year. In the EU, DORA has applied since January 2025 and requires financial entities to test the systems behind critical functions at least once a year. In India, RBI-regulated entities run periodic VAPT under the RBI's directions, and partner banks will ask any fintech for a recent report during vendor due diligence.
Our compliance guide compares the frameworks, and financial cybersecurity explained covers the wider threats.
How we keep testing safe
- Sandbox or staging environments with test funds
- Your side of each payment integration only, never the provider's systems
- A mutual NDA before you share anything
- Critical issues reported as soon as we confirm them
- A retest after your fixes, with an updated report
Fintech testing questions
Can you test our payment provider integration?
We test your side of it: how your app calls the provider, how it handles callbacks and whether it verifies webhook signatures. We do not test the provider's own systems, which needs their permission.
Do you test in production?
We prefer a sandbox or staging environment with test funds, so we can try abuse cases safely. Anything that must run in production is agreed in writing first.
Which reports do partner banks ask for?
Usually a recent penetration test report covering the product and its APIs, plus evidence that critical findings were fixed. A retest and updated report gives them that evidence.
How long does a fintech test take?
It depends on the number of products, roles and integrations. A single app with its API usually takes one to two weeks of testing. Testing can start within 48 hours of a signed scope.
Start your security assessment.
Tell us about your application, architecture or compliance requirements. Our team will scope a penetration test around them.