Cannot Verify PIN
A "Cannot Verify PIN" decline means a technical failure prevented the issuer from validating the PIN entered, such as encryption key mismatches or a system outage — it is distinct from an incorrect PIN entry. The cardholder's PIN may be entirely correct; the issue lies in the verification process itself rather than the credential.
Decline code by card network
| Card network | Code | Network's wording |
|---|---|---|
| Visa | 86 | Cannot Verify PIN |
| Mastercard | 86 | Cannot Verify PIN |
Common causes
- A PIN encryption key mismatch or configuration issue exists between the terminal, acquirer, and issuer's PIN verification system.
- The issuer's PIN verification system is temporarily down or experiencing a technical outage.
- The terminal's PIN pad hardware or software has a fault preventing proper encryption of the entered PIN.
What merchants should do
- Offer the customer a signature-based or chip-and-signature transaction if your terminal and card support a fallback method.
- Ask the customer to try again, since a temporary issuer-side outage can resolve within minutes.
- If the issue persists across multiple cards, contact your processor to check for a terminal or encryption key configuration problem.
How to prevent this
- Keep PIN pad terminal software, firmware, and encryption keys current and properly provisioned by your acquirer.
- Ensure your terminal fleet is regularly tested and certified for PIN verification after any hardware or software updates.
- Monitor for spikes in this specific code, which often indicate a terminal fault or issuer outage rather than isolated cardholder errors.
Because this decline reflects a breakdown in the verification process rather than a wrong PIN, offering a non-PIN fallback transaction method is often the fastest way to complete the sale. Persistent occurrences at a specific terminal warrant a hardware or configuration check.
Frequently asked questions
Does "Cannot Verify PIN" mean the customer typed the wrong PIN?
No — that would be a separate "Incorrect PIN" decline. "Cannot Verify PIN" means a technical problem prevented the verification process from completing at all, regardless of whether the PIN entered was correct.
What should we do if this happens repeatedly at one terminal?
Repeated occurrences at the same terminal usually point to a hardware, software, or encryption key problem, so it's worth having your processor inspect or re-provision that specific terminal.