When an authorization is voided via a gateway or credit card terminal on a credit card, that is indeed "settled" when the batch of transactions for the day is settled. That may take 24 to 48 ours to actually show on the customer's credit card account, but the process of voiding an authorization against a credit card happens as quickly as the various networks involved can process and show it (say on the customers online statement of recent activity).

 

However, with debit card authorizations, the void really does nothing at all. Once a bank has an authorization against a debit card, it will only drop when the bank lets it drop "naturally" if no force capture is run against that authorization. That is, it's completely up to the bank that issued the debit card as to when they will let an authorization that is not captured against fall off. Typically it is 7 to 14 days.

 

Without getting technical, essentially, an authorization on a debit card is an authorization against available cash -- the bank wants to be very conservative about that (they are the ones sitting on the money); while an authorization on a credit card is an authorization against credit extened -- and the credit card issuer has every interest in you having that borrowing power back to the customer ASAP (so they might have something to charge interest against).

 

So, when changing the amount of the original authorization before force capturing on a debit card, it's actually better to not void the original authorization, but instead to change the amount before forcing it. Then the original authorization will be adjusted on the force, rather like when you give a tip at a restaraunt or your hair stylist.

 

The bummer here, though is that there is no way to distinguish a debit card from a credit card programatically, and frankly, unless you have a lodging, restaurant or other type of merchant industry that requires tip out functionality, changing the amount of the original authorization is a no-no.