Is it wise to use a balance transfer credit card to allow a EU rental car company to hold the deposit?

Posted by _thetrue_SpaceTofu@reddit | AskUK | View on Reddit | 8 comments

We will be going on a trip to EU soon and already arranged a rental car. They made it clear that understandably they are going to need a credit card for the deposit. Would it be OK to use a balance transfer credit card? If I understand correctly, the amount for the deposit it is only allocated/frozen on the card and won't generate an actual transaction, therefore 1- we won't get stung by the high interest fees 2- we won't pay any currency conversion fee Are we all in agreement until now, I hope yes? However what happens if a damage is discovered upon returning the car? Will the credit card with the frozen amount be directly charged, or will it be possible for me to use a debit card? To note, I am aware that you can buy additional insurance to reduce the deposit, but I am not interested in that as I have a 3rd party insurance, which will of course refund me later on for the damage, but not any CC purchase fee or currency conversion fee.