What changed between PCI DSS 3.x and 4.0?
PCI DSS 4.0 introduced more detailed and, in places, stricter requirements than the 3.x series it replaced, including changes to authentication, monitoring, and how organizations are expected to demonstrate ongoing compliance rather than point-in-time compliance. Carrying an existing certification through that change means updating controls and evidence to match the new standard, not simply re-submitting the old documentation.