Calculating legally compliant rent late fees across U.S. states

[hrgdevBuilds]

I built a small tool to clarify how much late fee a landlord can legally charge (and when) in each U.S. state.

Rent laws vary widely: some states set a fixed dollar cap, others a percentage, and a few use only “reasonable” language that’s open to interpretation. Many renters and landlords have no easy way to check what’s actually allowed without reading the statutes themselves.

This project compiles those laws into an instant calculator. Enter rent amount, due date, payment date, and state — it shows the lawful late fee limit, grace period rules, and citation.

It started as a curiosity after seeing conflicting answers online. The goal is transparency, not advocacy; all data is drawn from current state statutes.

The app is lightweight, built in Replit, and runs entirely client-side. I’d be interested in feedback on legal interpretation consistency, data sourcing, or UI clarity.

[limagnolia]

Utah appears to be calculating incorrectly, the text says "10% of rent or $75, whichever is GREATER." But it is doing the opposite, showing the lessor of 10% or $75.

[axus]

I love the ambiguity in who the tool is for. For renters, learning about their rights and fighting illegal fees. For landlords, charging the maximum amount permitted under the law.

[candiddevmike]

I thought this would be for tenants, but this seems more geared towards landlords. Most landlords have some kind of SaaS platform that will automate all of this for them as part of rent collection, I don't think you'll get many bites on this TBH.

I'd love to see some kind of 50 state tenant resource center, geared towards providing tenants with advice and legal resources.

[pseudocomposer]

At least for North Carolina, it's wrong/self-inconsistent. The quoted text (and linked NC legislation) says the max is:

> $15 or 5% of rent, whichever is GREATER. 5-day grace period. One-time fee per late payment.

But this site seems to say the legal maximum is whichever is lower (i.e., it won't go above $15).

[ecshafer]

There are laws at the county and city levels as well as state levels. So this is insufficient.

[redmattred]

Curious what your process for gathering and verifying the legal information was

[bpt3]

Based on how inaccurate the information is and the fact that there is no support for local (city, county, town, etc.) regulations, I would say it was a very simple prompt to an LLM with no additional verification.

[shimmers]

Being a landlord is one of the most directly parasitical things a person can do to another person.

I see all the bugs here about how it minimizes fees by reversing a particular comparison, and for a second I got excited -- maybe it's a subversive site? But no, just AI blunders.

[dotnet00]

I don't know how I feel about the concept of late rent fees...

On one hand, you did agree to the payment schedule when you signed the lease, but on the other hand, tacking on fees to someone who is already struggling to pay, to support mainly parasites responsible for creating a lot of the issues facing young people, is also not great.

[everforward]

Not a landlord, but landlords have financial obligations they need to meet as well, and not getting rent can create issues there. They still have to pay taxes, insurance, repairs, etc.

I think late fees are fine, but shouldn't be enforceable in the event the lease is cancelled by either party (ie eviction or early termination). Tenants would still owe back rent, but not punitive fines for being unable to pay.

I'd also say there should be some method to punish landlords for illegal terms in leases, like late fees in excess of what the law allows. I watch court streams sometimes and the percentage of landlords who have illegally high late fees is shocking and I've never seen a punishment beyond "you can only tack on late fees of $X by law".

[bpodgursky]

People are lazy. Without penalties, nobody will ever pay a bill. Doesn't matter if they are rich or poor. They could have $1mm cash sitting on their desk and unless you motivate them, they're just not going to open the bill.

That's just the reality of sending bills or invoices. Half the time it's not about malice, just no reason to bother being timely.

[goldenCeasar]

This looks something that could work nicely with my calculation DSL (https://github.com/amuta/kumi) This is one of the scenarios that was in my head: auditable/exportable/reusable tax-related calculations schemas.

[nashashmi]

for nj the legal source brings up a 404. https://www.nj.gov/dca/divisions/codes/publications/pdf_lti/...

[josefritzishere]

Sounds like a great tool. But it's sad that it needs to exist.

[bpt3]

Sad in what way?

Renters will always exist, and some will be unable or unwilling to adhere to the contract they signed. Like all contracts, there are penalities for non-compliance (on both sides).

[SilverElfin]

Yep. A lot of these regulations end up hurting small landlords because only corporate landlords with a large number of units can comply easily and absorb costs of bad tenants.

[grafmax]

Our society prioritizes the narrow interests of rentier capitalists over the working class. Unfortunately this means the US is losing international competitiveness across more and more industries. For one thing rent extraction ultimately gets financed by employers through higher wages, thus productive business loses out to business from a region like China where costs of employment are lower. Rather than making economies more efficient like productive business is supposed to do, rentier capitalism means cash flows from the debtor to the creditor class, which forms a feedback loop as the creditor class is able to use this cash to buy more assets and extract more rent simply by expanding its circle of ownership.