Fintech pen testing before launch, funding or a banking partnership

For most fintechs, the first penetration test isn't driven by the security team. It's driven by someone else's due diligence: an investor, a sponsor bank, a card scheme, an enterprise client or an FCA authorisation application. That changes what a "good" test looks like.

Who asks, and what they want to see

• Investors want assurance there's no latent breach waiting to wreck the valuation. They'll ask whether you've been tested, when, by whom, and whether critical issues were fixed.
• Sponsor banks and BaaS partners have their own regulators and third-party risk teams. Expect detailed questionnaires and a request for the executive summary or attestation letter.
• Card schemes and acquirers bring PCI DSS. Requirement 11.4 calls for internal and external penetration testing at least annually and after significant change, plus segmentation testing if you rely on it to reduce scope.
• Enterprise clients send security questionnaires with "provide your latest pen test summary" on page one.

The mistakes that cost fintechs time

1. Testing too late. A test a week before the partnership deadline turns up a critical that needs a sprint to fix. Test four to six weeks ahead.
2. Testing the wrong thing. Your marketing site isn't your product. Scope the app, the API and the cloud environment it runs in.
3. Unauthenticated-only testing. Most serious fintech issues sit behind login: one user accessing another's account, transactions or KYC documents.
4. No retest. Due diligence teams want to see criticals and highs closed, not just reported.
5. A report you can't share. Ask for a separate executive summary or attestation letter you can hand to third parties without exposing technical detail.

What a fintech test should cover

• API authorisation: object-level and function-level access control (the OWASP API Top 10), across every role.
• Money movement logic: race conditions on balances and transfers, replayed requests, limit bypass, rounding and currency handling.
• Authentication and session handling: MFA bypass, account recovery abuse, token handling in mobile apps.
• KYC and document handling: upload abuse and access to other customers' identity documents.
• Cloud configuration: IAM, secrets management, storage exposure, CI/CD pipeline access.
• Mobile apps if you have them: local storage, certificate pinning, API keys in the binary.

The bottom line

Treat your first pen test as a sales asset, not a compliance chore. Scoped properly and done early, it shortens every partnership, funding round and enterprise deal that follows.

FAQs

When should a fintech get its first penetration test?

Four to six weeks before any launch, funding round, banking partnership or enterprise deal that will require test evidence, so there's time to fix and retest.

Does PCI DSS require penetration testing?

Yes. PCI DSS requirement 11.4 requires internal and external penetration testing at least annually and after significant changes, plus segmentation testing where segmentation is used to reduce scope.

Sources & further reading

• PCI DSS 4.0 testing requirements

Related reading

Related reading

• What the FCA actually expects from your penetration test
• DORA for UK firms: does it apply to you, and what testing does it expect?
• Pen testing for wealth and investment managers: five attack paths to test first