When PCI DSS v4.0 was initially released in March 2022, it sparked massive debates across the cybersecurity and digital payments industries. The standard introduced transformational changes—shifting the focus from static, point-in-time checklists to continuous, risk-based security validation.

Today, in 2026, the transition periods are officially over. Version 3.2.1 is obsolete, and all future-dated grace periods (which expired in March 2025) are now fully enforced, mandatory requirements. Organizations that process, store, or transmit cardholder data must maintain strict adherence to these advanced security controls.

To help businesses navigate this fully enforced standard, we have compiled and updated the most frequently asked questions regarding PCI DSS v4.0 implementation, technical mandates, and compliance strategies in 2026.

Part 1: The 2026 Compliance Reality

Q1. Can we still certify on PCI DSS v3.2.1 if our network hasn't fully transitioned?

No. PCI DSS version 3.2.1 was officially retired on March 31, 2024. Furthermore, the 64 "future-dated" requirements of v4.0 became strictly mandatory on March 31, 2025. In 2026, every single PCI DSS assessment must be conducted against the fully enforced v4.0 standard.

Q2. How do the PCI DSS v4.0 standards align with RBI guidelines in India?

‍The Reserve Bank of India (RBI) mandates highly robust cybersecurity architectures for all regulated entities in the payment ecosystem. Because PCI DSS v4.0 is now the only active global standard for card data, Indian banks and payment aggregators must comply with v4.0 to satisfy both international card brand requirements and the overarching cybersecurity expectations of the RBI.

Q3. How is PCI DSS compliance handled during a corporate Merger or Acquisition (M&A)?

‍The standard protocol applies. If you acquire a new company or merge IT infrastructures, you must perform a formal delta assessment immediately. Integrating an unverified network into your environment drastically expands your scope and risks introducing dormant threats. A gap assessment should be conducted, and all relevant security documents must be updated prior to your next formal re-certification.

Part 2: Technical Mandates and Architecture

Q4. Does PCI DSS v4.0 still allow disk-level encryption for Cardholder Data?

No. This is one of the most critical changes. Under v4.0, disk-level encryption (Full Disk Encryption) is no longer a valid mechanism to protect the Primary Account Number (PAN) stored on servers, because the data automatically decrypts when the operating system boots. Disk-level encryption is now only acceptable for removable electronic media (like USB drives). For non-removable media, you must render the PAN unreadable via data-level encryption, tokenization, or truncation. Utilizing an automated data discovery and classification tool is highly recommended to locate and encrypt rogue PAN data.

Q5. Do we need Multi-Factor Authentication (MFA) for physical security controls, like server room doors?

‍No. The strict new MFA mandates in PCI DSS v4.0 apply to logical access, not physical access. MFA is legally required for all remote access into the Cardholder Data Environment (CDE) and all non-console administrative access. While requiring dual-factor authentication (like a Biometric + PIN) for physical server room doors is an excellent security practice, the v4.0 MFA requirement is specifically targeting digital access.

Q6. Does v4.0 require us to use automated vulnerability scanning tools like Tenable or Qualys?

‍PCI DSS does not mandate a specific brand or force the choice between manual versus automated tools; the flexibility lies with the organization. However, v4.0 does mandate that internal vulnerability scans must be performed via authenticated scanning. Automated enterprise tools with integrated Threat Intelligence are highly recommended to accurately prioritize risks, provided the scanner logs directly into the system with credentials to evaluate deep-level missing patches and registry flaws.

Q7. Does v4.0 explicitly address data leakage and Data Loss Prevention (DLP)?

‍Yes. While it doesn't dictate a specific product, Requirement 11.5.1.1 (applicable to service providers) highlights the implementation of covert malware detection. Additionally, Appendix A3 (Designated Entities Supplemental Validation - DESV) mandates that mechanisms must be in place to detect and prevent cleartext PAN from leaving the CDE via any unauthorized channel, making DLP solutions highly relevant.

Part 3: The Customized Approach vs. Compensating Controls

Q8. What is the difference between Compensating Controls and the Customized Approach?

‍This is a frequent point of confusion.

• Compensating Controls are used when an organization cannot meet a stated requirement due to a documented technical or business constraint. You provide a justification and implement a workaround to mitigate the risk.
• The Customized Approach is for highly mature organizations that choose to implement an alternative, innovative security technology that meets the intent of the requirement, even if it doesn't follow the exact checklist. It does not require a business constraint justification, but it does require a rigorous Targeted Risk Analysis.

Q9. Can we mix and match the Defined Approach and Customized Approach?

‍Yes. An organization can toggle between the Defined Approach (the standard checklist) for 90% of its environment, and use the Customized Approach for the remaining 10% of highly complex, cloud-native architecture. You can even use different approaches to meet the exact same requirement across different system components.

Q10. Can third-party contractors manage a customized environment for us?

‍Yes, but with extreme caution. Because the Customized Approach relies entirely on advanced risk management practices, your third-party vendor must possess an exceptionally high level of security maturity. If a third-party manages your custom controls, you are still legally responsible for their effectiveness during your PCI DSS compliance audit.

Q11. Will the Customized Approach make my audit faster or cheaper?

‍Almost never. The Customized Approach provides architectural flexibility, not cost savings. It requires significantly more documentation from your internal teams (including a mandatory Targeted Risk Analysis for every custom control) and requires your Qualified Security Assessor (QSA) to write completely bespoke testing procedures to validate your unique technology.

Secure Your Payments Ecosystem with SISA

Achieving continuous compliance under PCI DSS v4.0 requires deep technical expertise, especially when navigating authenticated scanning and the Customized Approach.

As a globally recognized Qualified Security Assessor (QSA) and PCI Forensic Investigator (PFI), SISA helps organizations secure their payment ecosystems efficiently. Whether you need a formal Report on Compliance (RoC), an internal Network Vulnerability Assessment, or want to empower your IT teams through our ANAB-accredited CPISI Training programs, SISA's forensic-driven experts are ready to guide you.