Confirmed transactions cannot be undone
Blockchain transactions are irreversible once confirmed. Refund processes must therefore be operationally robust and well documented. Errors cannot be corrected through traditional banking reversals.
Where and how long transaction data is stored
Whether processor takes possession of funds
Risk of transaction being reversed before confirmation
Rules for mismatched payment amounts
Validation that a transaction is included in a block
Coins tokens and blockchains the processor supports