Response Code 97 indicates that the transaction fingerprint created to authenticate a Simple Integration Method (SIM) transaction has expired. This error is received when the timestamp value submitted in x_fp_timestamp is either 15 minutes ahead, or 15 minutes behind in Greenwich Mean Time (GMT) (this is the equivalent of 900 seconds ahead or 900 seconds behind in Coordinated Universal Time, or UTC).
The Response Code 97 troubleshooting tool validates whether the value you submitted to Authorize.Net for x_fp_timestamp is a valid timestamp. Valid timestamps must be formatted in UTC, which is the number of seconds since 12 AM, January 1, 1970.
To troubleshoot a Response Code 97, check the following:
Verify that the time on the Web server that hosts the SIM script is configured correctly to the GMT time zone. You can also modify the SIM script to format UTC.
If you are having consistent problems with your timestamp, make sure that the Web server that hosts your SIM script employs a Network Time Protocol (NTP) to regularly update the time.