Payment Application Security Testing

From transaction flow analysis to back-end API security, we test payment systems the way attackers target them. Fintech platforms, SoftPOS solutions, card-present and card-not-present environments, payment gateways, and merchant integrations.

Get a Payment Security Assessment

Payment systems are high-value targets

Payment applications process sensitive cardholder data, manage financial transactions, and integrate with multiple third-party services. A single vulnerability can lead to fraud, data breaches, regulatory fines, and loss of customer trust. Attackers specifically target payment flows because the reward is immediate and tangible.

We bring specialist knowledge of payment protocols, EMV specifications, tokenisation systems, and PCI compliance requirements to every engagement. Our testers understand how payment transactions work end-to-end, which means we test the attacks that matter to your specific payment ecosystem.

Payment Security Testing Services

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Transaction Flow Security

End-to-end testing of payment transaction flows from initiation through authorisation, capture, and settlement. We probe for manipulation of amounts, currency, merchant identifiers, and replay attacks at every stage of the process.

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Payment Gateway & API Testing

Security assessment of payment gateway integrations, merchant APIs, webhook endpoints, and callback mechanisms. We test authentication, authorisation, input validation, and business logic specific to payment processing.

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SoftPOS & Mobile Payments

Security testing for mobile payment acceptance solutions including COTS-native NFC, contactless kernel implementations, and PIN entry on mobile devices. Aligned to PCI MPoC requirements for SoftPOS vendors.

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Tokenisation & Encryption

Assessment of tokenisation implementations, point-to-point encryption (P2PE), key management practices, and cryptographic controls protecting cardholder data in transit and at rest.

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Merchant Integration Security

Testing the security of merchant-facing portals, onboarding systems, reporting dashboards, and the APIs used by merchants to manage transactions, refunds, and disputes.

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PCI Compliance Validation

Penetration testing aligned to PCI DSS and PCI MPoC requirements. Our reports satisfy Requirement 11.3 for annual penetration testing and provide evidence your assessor expects to see.

Who we work with

Fintech Companies

Payment startups, neobanks, and financial technology platforms that process, facilitate, or store payment data and need security validation for investors, partners, or compliance.

Payment Service Providers

PSPs, acquirers, and payment facilitators that manage merchant accounts and process transactions on behalf of others. PCI DSS Level 1 compliance support included.

SoftPOS Vendors

Companies building Mobile Payments on COTS solutions that need specialist MPoC penetration testing and consultancy for PCI lab evaluation and annual compliance.

E-commerce Platforms

Online merchants and marketplace platforms with custom payment integrations, stored card functionality, subscription billing, or multi-currency processing.

Banking & Financial Services

Banks, building societies, and financial institutions with digital payment products, open banking APIs, or customer-facing transaction systems.

Payment Hardware Vendors

Manufacturers of payment terminals, card readers, and connected payment devices requiring security validation before deployment.

Secure your payment systems

Tell us about your payment application and we'll scope a security assessment that covers the risks specific to your transaction flows and compliance requirements.

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