For details on Forte error codes, please refer to below link:
Description of few common errors is stated below:
U10: DUPLICATE TRANSACTION - Forte has a default 5min timer preventing accidental duplicate transactions from the same card same amount. If you want to change this timer or remove it altogether just send an email to firstname.lastname@example.org with your merchant ID
U83: NSF - means that there are Not sufficient funds in donor's bank account
U83: INVALID ACCT - It is due to new card issued to the donor. Please contact donor for updated credit card information
U83: DECLINE - card declined by the card issuer Visa, MC, Amex, Discover
U02 ACCOUNT NOT APPROVED- Customer account is in Forte's "known bad" account list (EFT only). Please send email to Forte's customer service at email@example.com or call 866.290.5400 Option 1, Monday – Friday, 7am – 7pm CST. with your Merchant ID, error code, donor's name and transaction details for resolution of the issue. They will assist you in this regard.
Authentication Is Invalid - This error occurs due to incorrect Forte credentials. In order to resolve this issue, please send email to Forte's customer service at firstname.lastname@example.org or call 866.290.5400 Option 1, Monday – Friday, 7am – 7pm CST. with your Merchant ID, API Login ID, Real-Time Password and Secure Transaction Key.
FORTE ERROR (doDirectPayment): E: Email is invalid is an error only due to incorrect email address of donor; it's not a decline therefore transaction will be processed and credited into their bank account.
R03 - Unable to Locate Account : Account number entered did not correspond to an actual bank account so the Forte was not able to pull funds. Most likely there was an error in either the bank account or routing no. Please contact the donor to confirm the bank info