Response Code 99 indicates that the payment gateway could not authenticate the transaction fingerprint submitted for a Server Integration Method (SIM) transaction. This error is received when the transaction fingerprint recreated by the payment gateway does not match the transaction fingerprint submitted in x_fp_hash.
For more information about generating transaction fingerprints, please see the SIM Integration Guide at http://developer.authorize.net/guides/SIM/.
The Response Code 99 troubleshooting tool allows you to enter and validate your fingerprint input values against Authorize.Net application programming interface (API) formatting requirements and generates the correct transaction fingerprint. You can use this tool to compare fingerprints and determine and fix any possible input value formatting errors.
The generated fingerprint:
Verify that you are using the current transaction key.
Obtain a new transaction key in the Merchant Interface and update all scripts that require a transaction key accordingly.
Please note that once a new transaction key has been obtained, the old transaction key will expire and become invalid after 24 hours. Be sure that all sites using SIM are updated with the new transaction key before the old key expires.
To obtain a transaction key:
Remember to store the transaction key in a secure location. Do not share it with anyone, as it is used to protect your transactions.