1. Authentication controls
Checklist point 1: MFA enforcement across all user roles
Does every user on your platform authenticate with more than just a password? MFA enforcement is the single highest-return security control, yet many fintech teams implement it inconsistently. App-based authenticators and biometrics reduce credential-based attacks by roughly 80%. SMS-based MFA creates a SIM-swapping exposure that attackers actively exploit. The stronger path is FIDO2 and WebAuthn for passwordless flows combined with risk-based prompts. See our authentication security service for a professional review.
Checklist point 2: Session management and device tracking
Authentication doesn't end at login. A strong session policy covers rate limiting on failed attempts, device fingerprinting, IP tracking, and automatic session termination on anomalous behaviour. Reviewing your session timeout settings and device alert logs is a good 15-minute starting point.
2. API and mobile app vulnerabilities
Checklist point 3: Testing for BOLA, IDOR, and injection risks
API vulnerabilities cause more fintech breaches than most teams realise. Broken Object Level Authorization (BOLA) and IDOR top the OWASP API Security Top 10. The Revolut incident exposed approximately 50,000 customer records through authorisation gaps. For a deep-dive into BOLA specifically, see our article on the most dangerous API vulnerability in payment platforms.
A quick directional test: intercept an authenticated request and swap the account or object ID. If the server returns data, your authorisation layer isn't checking ownership. For a thorough API review, see our API security testing service.
Checklist point 4: Mobile app security hygiene
Check whether sensitive data is stored in plain text locally, whether all traffic routes over HTTPS with certificate pinning, whether token TTLs are short enough, and whether the app passes basic static analysis via MobSF.
3. Data encryption and access control
Checklist point 5: Encryption in transit and at rest
"We use encryption" tells a compliance reviewer nothing. The specific standard matters: TLS 1.2+ for data in transit and AES-256 at rest. Run your domain through SSL Labs' free server test. If you see TLS 1.0 or 1.1 still enabled, that is a direct red flag for PCI DSS reviews and banking partners.
Checklist point 6: Role-based access and least-privilege
Does every internal user have access only to what their role requires? Over-permissioned internal accounts are a common and under-appreciated risk. A least-privilege audit means mapping current access grants to actual role requirements and setting a recurring review cadence. Quarterly is a reasonable minimum for high-growth teams.
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Get a Security Assessment4. Fraud detection and transaction monitoring
Checklist point 7: Rules engines and real-time alerts
A functional fraud detection stack starts with a rules engine: predefined thresholds for transaction velocity, unusual amounts, high-risk geographies, and account behaviour patterns. Can your system catch a credential-stuffing attack at 6 AM before your engineering team is online?
Checklist point 8: ML anomaly detection and KYC controls
Rules engines catch known patterns. Machine learning catches the patterns you haven't written rules for yet. KYC onboarding should use biometric verification, device fingerprinting, and AML screening together. For related regulatory requirements, see our CBN compliance guide.
5. Certifications and penetration testing cadence
Checklist point 9: SOC 2, ISO 27001, and PCI DSS status
SOC 2 Type II is the baseline for US enterprise partnerships. PCI DSS Level 1 is mandatory if you touch cardholder data. ISO 27001 matters for global expansion. Red flags: certifications with no stated audit period, reports older than 12 months, or vendors who offer a summary instead of the actual report. For details, see our pentest certifications guide.
Annual penetration tests are the minimum. Quarterly testing for high-risk components, particularly public APIs and authentication flows, reflects a more mature posture. For details on what testing looks like, see how a Simpa Labs pentest works.
6. Deposit insurance and banking partner verification
Checklist point 10: FDIC pass-through coverage
Fintechs don't hold FDIC insurance directly. Pass-through coverage works only when three conditions are met: funds are owned by the end user, the account at the bank is properly titled, and the bank maintains accurate records. Verify your banking partner's FDIC status on the FDIC's BankFind tool. See the FDIC's guidance on pass-through deposit insurance coverage.
Self-assessment complete?
If you found gaps, that's not a failure. It's exactly what this checklist is for. The practical next step is a structured security assessment from a team that specialises in fintech. The indicators you've worked through here are the same ones a professional audit starts with. The difference is depth, rigour, and an independent opinion that holds up in a compliance conversation.
Related reading
Blog: Do fintechs need a security audit before launch? · Fintech API security: 10 steps · Would hackers really attack my fintech?
Guides: Fintech security checklist · VA vs pentest · OWASP for fintech
Services: Penetration testing · API security · For digital banking and lending platforms