Anyone know much about pre-authorisation/deferred c/card payments?

[Lorna Doone]

I'm wondering if I would get charged any fees for a pre-authorisation payment taken by c/card? I need to take a security bond from customers as I'm hiring out a vehicle, but this needs to be refunded upon safe return of the vehicle. A pre-auth/deferred payment would make sense as I could (presumably) just reverse it without physically taking any money from their c/card account, but will I be charged by my merchant account bank for doing this?

 

[Ozzy]

You will be charged for part of the transaction, depending on who you used to do the Pre-Auth.

A pre-auth does (sort of) take the money from the persons card so that they cannot spend it. It allocates the money to you ready for you to claim if and when you need to, so for example...

Customer has a £1,000 credit limit on their card and they have spent £250 already. You then Pre-Auth £500 on their card, which means they will only have £250 remaining credit on their card until you either cancel the pre-auth or the time frame it is valid for lapses. However they will not be charged interest on this pre-auth transaction because they have not actually spent the money - it's just held in standby if you will.
So as a merchant a transaction has taken place, albiet only 50% of one, so you will be charged but the exact amount I don't know.