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.
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.
I always thought Replit was supposed to be a pastebin site with built-in sandboxed code execution, so people could demo Python snippets and what-not. What happened?
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.
Here on Long Island (NY), most apartments are illegal (addition/remodeled single-family homes). Many of them make you sign a lease, anyway, but they can get dismissed by any law student.
Every now and then, some municipality claims that it will be "fighting illegal apartments," but they die quick deaths. If they got serious about it, the homeless population would explode, and a lot of folks would leave the state.
Also, I believe that most of the rules that apply to apartments, come from municipalities, not states.
This is the failure mode of bureaucratic government. The personality type of bureaucrats means that the rules will proliferate endlessly. Karens never sleep. Eventually the rules get so onerous that it becomes impossible to comply and everybody operates in violation of the rules. Everybody know that actual enforcement of the rules would be catastrophic, so they noncompliance is ignored. The economy reverts to the same unregulated and "unfair" state that the ruling Karens feared in the first place, but arbitrary enforcement continues anyway as the bureaucrats need to justify their existence by continually enforcing the rules. The number one rule of business becomes "keep your head down" because anything that attracts the attention of the bureaucrats will be immediately enforced, while the other 99% of violators are allowed to peacefully continue violating. Stagnation and slow decay takes hold as any sort of disruptive innovation is instantly shut down.
The "true" failure mode is bureaucrats discovering they can collect bribes from 99% of businesses to not enforce the rules, since nobody notices noncompliance and enforcement is expectedly arbitrary.
When I am dictatorKing, I will make the first line of the constitution (which won't matter because I'm dictatorKing (yes, the camelCase is important (yes I'm nesting parentheses))) be that a mandatory and invulnerable defense against any crime, claim, or tort is that the law is not enforced regularly.
How does that work for something like speeding, where they will charge you with everything, then let you off with a different infraction that doesn't actually have anything to do with the laws you supposedly broke.
They do that enough times, and all of a sudden now speeding is legal because no one was charged with speeding, but with "driving with an invalid instrument".
This would basically get rid of the "easy plea downs" and basically make fighting against the book the norm.
IRL example:
I once pulled out of my driveway and passed a stopped school bus (with lights on, but no stop signs extended) on a divided highway (barrier between my side of the road and theirs), a cop saw me do that, went around the barrier and pulled me over a couple minutes later. I was charged with something that was going to instantly take my license away.
I went to my local courthouse on the designated day, the prosecuter brought me in and told me he would drop the charges to failure to stop at a stop sign. I said I didn't pass a stop sign, and that the bus didn't have them extended, just stopped with lights on, across a highway from me.
Prosecutor said, that I'm allowed to argue that in front of a judge along with paying some large sum, and potentially lose my license, or take a point, and pay $150 today and be done with it.
>Here on Long Island (NY), most apartments are illegal (addition/remodeled single-family homes). Many of them make you sign a lease, anyway, but they can get dismissed by any law student.
What does this mean in practice? Courts won't enforce late fees or unpaid rents? Landlords can't evict bad tenants? Renters can terminate leases without any penalty?
> Landlords get in a lot of trouble, for renting illegal apartments.
Do you have a source for this because I’m not convinced. Maybe a small portion do but the majority face no penalties. When I was in college the number of questionably legal homes for rent was insane, but I didn’t have time to go after them. A friend of mine did and won, but it required a lot of time. Most of the time the landlord does what they want and the renters don’t have the resources to go after them.
You make it sound like it’s the renters who take advantage of the landlords but most of the time it’s the landlords who do whatever they want. The ones who stopped paying rent probably were doing so legally because a lot of them were forced to not work.
Anything legal involves time and effort, but you certainly cannot do a "rapid eviction" on an illegal or unscheduled apartment.
Landlords naturally (e.g., by the nature) have the upper hand because they have the desired thing - the rental.
Tenants often have the legal upper hand, but the whole job of the landlord (even good ones!) is to work out which tenants know how to play the game and not rent to them.
In this case it sounds like "do whatever they want" for the landlords means entering into a mutually agreed upon contract to rent their house when they aren't allowed to by the nonsensical nitpicky rules. But "do whatever they want" for the tenants means squatting. So, yeah, it sounds like the tenants are the ones taking advantage. Tenants can get away with murder.
Look at rentals in college towns… education is already expensive so the tenants just want cheap housing. This attracts many landlords of the slumlord variety but because there’s a contract involved they’re given a pass. But even then they don’t necessarily abide by the contract and students don’t have the time and money to deal with small claims court so they just pay up (or accept the loss). Landlords absolutely take advantage of this situation.
As for squatters, yeah they’re taking advantage of lax enforcement but they’re few and far between despite what you’d read on the internet.
> Tenants can get away with murder.
Sounds like hyperbole
I guess my rant is just that renters get shit on because of a few squatters but landlords barely ever get criticized because there’s a contract involved. Some of the stuff I’ve read on the contracts isn’t even legal but a lot of tenants aren’t savvy to cross check laws or they’re owned by huge conglomerates who use stuff like RealPage.
I will admit to some bias here. I have been renting now for 22 years and have never had anything beyond a minor problem with a landlord that couldn't be resolved by a phone call. This seems to be the case for 90% of people I know. Then there's that person that is always having problems with landlords / neighbors and I tend to think the problem isn't actually the landlord / neighbors.
Yeah I can understand. In college I certainly lived with some folks who trashed the place. After I graduated and rented in nicer parts I haven’t had as much of an issue. Except most of them want to keep as much of the security deposit as possible and start coming up with bullshit costs with no itemization. I admit I’m biased against landlords - I hate how much of the costs can be passed down to the renter, like they aren’t making enough already. The best ones IME are the ones who have one or two properties, and the ones who have close to a dozen are a nightmare. Never been happier after buying my own place.
This is completely irrelevant to anything. It's none of the business of the tenant how much the landlord is profiting, and it's the obligation of the landlord to return the deposit fairly even if he is losing money on the property. Your experience is the opposite of mine in terms of small vs large landlords. Where I'm from the corporate landlords don't even charge deposits when you have good credit and income.
> This is completely irrelevant to anything. It's none of the business of the tenant how much the landlord is profiting
It certainly feels relevant when they start making excuses about why they have to charge you for things they cannot charge you for, claiming how expensive things are now. Operating costs have gone up for everyone, that doesn’t mean you get make things up to pass down the cost. But I do understand your point.
> Where I'm from the corporate landlords don't even charge deposits when you have good credit and income.
True, that has been my experience as well and I wasn’t explicit about that. The last couple of places we rented were from corporate ones and have had 0 issues compared to the mom and pop ones.
Around here, most of the landlords are people just like you. They own a house, and want to get a bigger one, so they either rent the old house (those are often legal rentals), or they divide the house they live in (or their old house), and rent the apartments (those are the ones that are usually illegal).
They aren't land barons or slumlords, and they get pretty screwed, when tenants abuse them. They can lose everything. One family I knew, had to let the house go into foreclosure, because the tenant refused to move, and refused to pay rent. I don't know what happened, after that, but I know that it's nearly impossible to sell a house that's occupied, and the tenants will often abuse the house before they are evicted (which can take months).
Yes, at least in some towns on the US east coast, if you didn't register your rental with the town. And not only that, but you also would have to pay treble damages and all moving costs associated with them vacating your illegal rental.
Would be an interesting service if someone developed a scraper to identify these illegal rentals. Why get an airbnb when you can get paid to stay somewhere for a few months?
It’s not the homeless population, it’s more to do to with the folks who own the apartments. Local politics and local real estate are birds of a feather.
Everybody wants to charge as much as he can. Workers do the same: we all want to charge as much for our labour as possible. Unions do the same thing too.
Everyone also wants to pay as little as he can, too.
Fortunately, as long as there are many buyers and many sellers, the market tends to find efficient prices. When there is a monopoly or a monopsony, though, prices get out of wack.
One thing I've noticed is that our current economic model, which builds in constant inflation, forces buyers and sellers to have this conversation non-stop. Why are prices higher? Because our costs are higher. Or because everyone else is charging more. Didn't you just raise prices recently? Yes...
If you don't increase your prices with inflation, your business will not be sustainable in the long term.
Not everybody everybody. Some people want to charge/pay/receive the maximum reasonable amount. Where "reasonable" is informed by social norms. The existence of so many amoral corporations, and sociopathic individuals running them, has absolutely skewed social expectations though.
Such people are certainly less common, but they do exist (anecdata of one, me)
My experience is that kids have to be taught “‘fair’ is what the market will bear” because they start out feeling quite strongly that it’s not true.
Tons of kids aren’t taught that, some of them start businesses, and they may struggle to make ends meet (or at least to thrive like they could be) because raising prices to market rates feels so unfair to them that they won’t do it unless prodded to and told it’s ok by someone else (and they still might not)
I definitely am not convinced market-rate-is-ethical-and-fair is natural thinking for most people, or the kind of thing they want to do.
(I’ve been the one telling people they should raise prices and I still can’t shake the feeling that it’s kinda wrong…)
> kids have to be taught “‘fair’ is what the market will bear”
Because it seems like the normal default for humans is that "fair" means when I sell something I take the highest offer I can get, but when I buy things the seller should give me the lowest offer he can while meeting his expenses or he is being "greedy." If you don't believe me just read the HN comments on any financial topic.
Nope, it works both ways, at least for lots of folks. The other attitude often (in my experience, most of the time) has to be explicitly taught or conditioned in from getting fucked enough times and deciding you may as well be fucking people too.
If you look at the other tools on the page, there's stuff for property-management and sending rent-reminders. I guess they know what part of their userbase is the most moneyed.
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.
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.