Frequently Asked Questions

Truncation is a method of rendering a full PAN unreadable by permanently removing a segment of PAN data, and applies to PANs that are electronically stored (for example, in files, databases, etc.).  

Acceptable truncation formats for different PAN lengths are as follows:

• The currently accepted format for all PAN lengths across all Payment Brands allows for a maximum of first 6 and last 4 digits of the PAN to be retained (described as: “First 6, last 4”).
• Entities seeking flexibility beyond the currently accepted truncation format must first understand the purposes to which the truncated data may be put, as well as any internal and/or external constraints (including Payment Brand requirements) that may need to be satisfied, before making changes.  If all such constraints are satisfied, entities seeking flexibility may consider the following: 

When using truncation formats for purposes other than storage, entities should confirm that their format is compatible with each of the applicable payment networks.  

Note: Access to different truncation formats of the same PAN greatly increases the ability to reconstruct full PAN, and the security value provided by an individual truncated PAN is significantly reduced.  If the same PAN is truncated using more than one truncation format (for example, different truncation formats are used on different systems), additional controls should be in place to ensure that the truncated versions cannot be correlated to reconstruct additional digits of the original PAN.