10% Late Fee Too Much??

[Marcin C.]

Hello everyone, I came across a few articles where landlords said they use a 10% late fee for rent, is this too high to be upheld in court if it came to it? I also read somewhere that judges won't uphold excessive late fees in court. I live in Michigan and I don't know if it's the same across all states or if there is anywhere I can find out if a 10% late fee is excessive. The rent I currently charge is $850 per month making the late fee $85 if the tenant is late on rent. If anybody could help with this question it would be much appreciated! Thank you BP!