Nexmo Verify generates 'Time-Based One-Time' PIN codes according to RFC 6238
- PIN default length is 4 digits and can be set per API call to 6
- PIN expiry time is 5 minutes by default
If a PIN code expires during a workflow in progress, a new PIN will be generated for this verification request for the next attempt. This means that the old PIN is no longer valid. Any future verification checks for this request will need to use the new PIN.