Dollar-and-cent amount of the charge for the purchase.
This field is optional and has a maximum length of 9 characters, the format is as follows: "-99999.99" or "+99999.99". It contains the total dollar-and-cent amount ($$$$$.cc) of the charge that the cardholder paid the merchant for the ability to perform the transaction. Position 1 contains the surcharge prefix. Positions 2-9 contain the surcharge amount.
Note: This is a reporting field only. Therefore the SurchargeAmount must be accounted for within TransactionAmount.
Note: The decimal point is required to be specified within the amount.