Do i have to apply to my first uni accomodation? or can i apply to two?

I've neglected doing my uni accomodation as ive always been a kind of last minute type person and ive been looking around a bit and cant find a definitive answer to this question i have. So Im pretty sure that i wont make it into my first uni choice but does that mean that i still have to apply to it instead of my second which im more positive that i will end up going? thanks