PCI S3 (Secure Software Standard)
Assess and validate payment software to ensure alignment with PCI S3 requirements.
Why it matters
Meeting PCI S3 requirements requires organizations to demonstrate that security is embedded across application design, data handling, and operational controls.
Difficulty determining whether an application qualifies as in-scope payment software
Unclear scope boundaries across components, interfaces, and dependencies
Gaps in application-level controls related to authentication, encryption, and logging
Limited visibility into payment data flows and trust boundaries
Pressure to remediate gaps without affecting release timelines
Challenges preparing clear evidence for PCI SSC review and listing
Our Approach
SISA follows a structured and PCI SSC-aligned methodology to help software vendors assess application security, close critical gaps, and move toward successful PCI S3 validation with confidence.
Determine whether the application meets the PCI S3 definition of payment software, identify in-scope components, and establish clear scope boundaries.
Review architecture, payment data flows, and trust boundaries to confirm secure handling of payment data across the application.
Evaluate application-level controls against PCI S3 requirements across secure coding, authentication, encryption, logging, and vulnerability management.
Provide practical guidance to address identified gaps while minimizing disruption to business operations and release cycles.
Support formal PCI S3 assessment activities, documentation, evidence preparation, and validation readiness for PCI SSC listing.
Service Offerings
Our services support payment software vendors and service providers across the PCI S3 lifecycle, from readiness assessments to formal validation.
PCI S3 Readiness Assessment
Secure Architecture & Design Review
Secure Development Lifecycle (SDLC) Validation
Application Security Testing
PCI S3 Validation & Certification Support

BENEFITS
Strengthen Software Security and Build Market Confidence
A strong and independently assessed application security posture
Reduced likelihood of downstream PCI DSS observations in customer environments
Improved trust with customers, partners, and regulators
Higher confidence in secure coding and software security controls
Smoother PCI SSC validation and software listing outcomes
WHY SISA
Why Leading Payment Software Vendors Choose SISA
Recognized PCI Software Security Expertise:
Recognized PCI Software Security Expertise:
SISA is among the top PCI Qualified Software Assessor companies globally, with strong experience helping vendors validate and list software with PCI SSC.
Strong SDLC & Governance Expertise:
Hands-on experience aligning development practices with PCI SSLC expectations.
Business-Aligned Security Approach:
Security improvements without slowing down development teams.
Clear, Defensible Evidence:
Well-structured documentation to support PCI SSC review.
Trusted Advisor to Payment Ecosystem:
Preferred partner for banks, fintech’s, and payment software vendors.
Audit-Ready Deliverables:
Clear documentation and defensible evidence that stand up to PCI SSC review.
Want to know more?
FAQs
The PCI Secure Software Standard (PCI S3) is a compliance framework under the PCI Software Security Framework (SSF). It provides security requirements to ensure that payment software is designed, developed, and maintained securely to protect payment transactions and data.
Yes, the PCI Secure Software Standard (PCI S3), alongside the Secure SLC Standard, officially replaced the Payment Application Data Security Standard (PA-DSS). This transition addresses modern software development practices, including cloud-native environments, continuous integration, and agile methodologies.
Software vendors that develop payment applications intended for sale and distribution to third parties must achieve PCI S3 validation. This ensures to their clients that the software securely handles, stores, and transmits cardholder data.
PCI S3 focuses on the security features and vulnerability mitigation of the payment software itself. Secure SLC (Software Lifecycle) focuses on the vendor's internal development processes, ensuring security is integrated throughout the entire software creation lifecycle.
SISA conducts PCI S3 assessments using a structured methodology that includes scoping, a detailed gap assessment against SSF requirements, application architecture review, remediation guidance, and validation support. As a certified Secure Software Framework (SSF) Assessor Company, SISA ensures your payment software meets all mandated security design and development standards.
Yes, SISA provides specialized transition services for vendors moving from legacy PA-DSS to the modern PCI Secure Software Standard. Our experts perform delta assessments to identify specific gaps between your existing PA-DSS controls and the new S3 requirements, streamlining the upgrade process.
Yes, SISA goes beyond traditional auditing by offering actionable remediation support. If vulnerabilities or compliance gaps are identified during the initial assessment, our security experts provide clear, technical guidance on how to resolve them before the final validation report is generated.


