PCI DSS Requirement 3.3 requires that no more than the first six and/or last four digits of the PAN are displayed on computer screens, reports, etc. unless there is a documented business justification for seeing more digits. The documented business justification should explain why that person (or role) needs to see more digits of PAN, be approved by management, and available for an assessor to review as part of the PCI DSS assessment.
PCI DSS Requirement 3.4 applies when PAN is stored (i.e., data at rest). This requirement specifies four acceptable methods for rendering PAN unreadable when stored. One of the techniques is truncation, which permanently removes the middle digits of the PAN, leaving the rest of the PAN to be stored in the clear. FAQ #1091 What are acceptable formats for truncation of primary account numbers? provides information about acceptable truncation formats for each payment brand based on the length of PAN/BIN. Because each payment brand has different PAN/BIN lengths and different requirements, questions on payment brand truncation requirements should be directed to the applicable payment brands. Contact details for the payment brands are provided in FAQ #1142 How do I contact the payment card brands?
Please note that truncation is only one acceptable method for rendering PAN unreadable during storage; other options include encrypting the entire PAN, using index tokens, or using one-way hashes.
Article Number 1492