Generally speaking, if you return your rental car any later than the time designated on your contract, you will be charged a late fee. Certain companies will allow up to a 59 minute grace period for a late return but be sure to check your rental company’s policies before assuming that you do have that luxury.
Though it may seem unfair to be charged for returning a vehicle late, there is a reason why rental companies do. There are only a certain number of vehicles at any given location and it is likely that somebody else has the same car that you rented reserved for a time shortly following your contracted drop off time. The company needs to clean out and inspect the vehicle before renting it out again, which takes time. This may end up losing them business in the form of an agitated customer, fed-up with having to wait for their rental to be ready.
As long as you are aware of the rental company’s late return policy, and what it entails, you can act accordingly. You don’t want to lose money to unnecessary and avoidable charges.