Frequently Asked Question
What are acceptable formats for truncation of primary account numbers?
Acceptable truncation formats vary according to PAN length and Participating Payment Brand requirements.
- A maximum of the first 6 and last 4 digits of the PAN is the starting baseline for entities to retain after truncation, considering the business needs and purposes for which the PAN is used.
- When more digits of the PAN are necessary for business functions, entities should consult the table below for the acceptable formats for each Participating Payment Brand.
| PAN / BIN Length | Payment Brand | Acceptable PAN Truncation Formats |
|---|---|---|
| 16-digit PAN (with either 6- or 8-digit BIN) | Discover | At least 4 digits removed. Maximum digits which may be retained: |
| 15-digit PAN | American Express | At least 5 digits removed. Maximum digits which may be retained: |
| <15-digit PAN | Discover | Maximum digits which may be retained: |
When using truncation formats for purposes other than storage, or for PAN lengths not covered within this FAQ, entities should confirm that their format is compatible with each of the applicable Participating Payment Brands. Contact information for the Participating Payment Brands can be found in FAQ 1142 How do I contact the payment card brands?
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. Information about the use of different truncation formats of the same PAN can be found in FAQ 1117 Are truncated Primary Account Numbers (PAN) required to be protected in accordance with PCI DSS?