Everything I have found while researching this is that late fees are illegal to charge. All a landlord can ask for are recoverys of out of pocket costs or bank interest lost(I still don't know if this is valid) for a returned check. If payment isn't received, all a landlord can do is file a 3 day notice to pay or quit. There is no way to justify the monies charged for just being late. To keep the peace, I payed the late fee. But yes, I see that it should be considered overpaying and will ask for it back when the time comes.