
PCI DSS 4.0 Compliance Guide for Small Merchants in 2026
PCI DSS 4.0's transition period ended March 31, 2025, so every merchant assessment from 2026 onward now enforces mandatory payment-page script monitoring, MFA for all cardholder-data access, and authenticated internal vulnerability scans — noncompliance risks $5,000-$100,000 monthly fines from acquiring banks plus an average $173,692 added breach cost per IBM's research.









