Transactions in the BIP have a corresponding code (For successful transactions, the code is 000.000.000). Failed transactions have error codes that can give you an indication as to why the transaction failed. Below is a breakdown of the most common failed transaction codes as well as a brief explanation of what they mean.

100.390.109 Transaction rejected because of VISA status "U" or AMEX status "N" or "U" in 3D System This error often means that when the transaction was processed, the 3DSecure system at BanServ was down and therefore the transaction could not be authenticated.
100.390.112Technical Error in 3DSecure system This error is caused by a technical error in the 3DSecure workflow, this error is often isolated and the customer should be urged to try again after a couple of minutes.
900.100.300Communication Error (70) No response from Connector/Acquirer [Uncertain result] Communication Errors (similar to 900.100.100 and 900.100.600) occur when the customer tries to make a transaction when the acquiring partner (Nedbank) or BankServ is experiencing a downtime. Whenever this Error code is experienced, please report this to immediately to prevent further transaction additional failed transactions.
800.100.152Transaction declined by authorization system This is the general response provided by the bank when the issuing (Customer’s) bank declines the transaction. This could be due to various reasons i.e. when the card was reported stolen, if the bank’s internal risk settings flag and reject the transaction. This error is also experienced when the customer has insufficient funds. No further action can be taken by Peach Payments for this Error code.
700.400.100Cannot Capture (PA Value exceeded, PA reverted or Invalid Workflow?) You will often see this error is the Pre-Authorization you are attempting to capture was already captured, when you are trying to capture more than you are pre-authorized for as well as when you try to capture a reversed Pre-Authorization.
100.380.501Risk Management Timeout This happens when the customer abandons the 3DSecure page (leaves the page without entering their OTP) then the 3DSecure window expires and this message is returned to our system.