My son is a college student. His college lease increased in June. He said his new rent was $625. It turns out that it was $635. We sent a timely check for $625 each month. This week we discovered (by chance) that we were charged a $50 late fee each month - that is $150 for a $30 error. Is there a legal limit to the amount that can be charged as a late fee. If this was called interest, it would be a usurious rate.

Read the lease. From what I understand they can only go by a percentage of the late fee since most of it was paid.

Like if the late fee is $10.00 for $100. And you pay 90 then there would be a late fee of $1.00 because he was not late on the entire amount.
They can only charge the late fee for the percentage that hasn't been paid.

turns out that it was $635. We sent a timely check for $625 each month. This week we discovered (by chance) that we were charged a $50 late fee each month - that is $150 for a $30 error. Hello too:

I see that you were charged... But, did you pay?? If not, then I wouldn't, and make them sue you. Let a judge determine what's so.

excon

The question is does he have anything showing the rent as $625?

But I agree with excon, go back to the landlord and explain to them it was mistake. Also tell them, that your son received nothing to indicate his rent was considered late. Had then sent him a notice he would have corrected the problem immediately.

So offer to pay $50 for the one month to settle the charges. If not, let them sue him for the amount. I doubt if a court will allow them the whole $150.