We rent uhaul equipment where I work at. Up until recently all they did was verify that there was $1 available on the card, to make sure it was a legit card. No more of that, they finally got smart and figured out how many people didnt have anything on their cards and they were getting shafted for rentals. So now on a $30 truck they are getting $90 approved on the card for one day, for 2 days it's like 120, for 3 150 etc etc. Sorry to say there are way too many people out there that really dont have respect for others property, or would just drop equipment off where ever they felt like, leave lots of trash and such in it etc etc. I'm sure the rental car companies were running into the same thing. Just switch places with them, if you were going to rent your car to someone that you didnt know, would'nt you like to make sure you could at least cover a tank of gas, a minor scratch etc et before letting someone take you car? My only suggestion now would be to find out how much they will hold against your card. If it's 300 bucks, just pretend that you have that much less of a credit limit, it's not you are actually being charged that amount and paying interest on it, they are just reserving their fair share in case you dont follow thru on the promises you signed on the contracts. And trust me, even the low amounts of rentals we do, you'd be amazed at the folks that dont return the trucks on time, causing a problem for the next family, cant seem to read / operate a fuel pump properly etc etc.