Rent rules come from three places, in this order: the lease, state law and, in some places, city or county law. There is no national rent cap, no national notice period for a raise and no national rule on late fees. So almost every rent question, from a partial first month to a fee on a late payment, comes down to what the lease says and what your state and city add to it.
This page is general information, not legal or tax advice. Landlord and tenant law varies by state and city, and changes. Ask the court, your state agency, a lawyer or legal aid about your case.
This section follows rent through a tenancy: the first and last partial months, a raise and the notice it needs, and what happens when rent is late. Each part links to a full guide or calculator with the statutes and the dates we read them. It is written first for small landlords, and tenants can use it to check a rule. Landlord Rulebook sells nothing and refers no one.
The first and last month: prorating rent
A tenancy rarely starts on the 1st. Prorating means charging only for the days of a partial month, and there are three common ways to work out the daily rate: the actual days in that month, a 30-day month, or a year’s rent over 365 days. On $1,500 rent and a move-in on 12 December 2026, counting the move-in day, those come to $967.74, $1,000.00 and $986.30. In February the order flips, so no method always favors one side.
The lease usually decides which method applies. Florida, Arizona, Kansas and South Carolina say rent is apportionable from day to day “unless otherwise agreed” (for example F.S. 83.46(1)), and none of those sentences says whether to divide by 30 or by the actual month. Minnesota goes further for a final partial month: actual calendar days, with no waiver (Minn. Stat. 504B.116, read 5 November 2026).
Our prorated rent calculator gives an estimate by all three methods side by side, handles move-ins, move-outs and leap-year Februaries, and lists the state sections we read. The worth of a lease line saying which method applies is easiest to see there, before anyone signs.
Raising the rent: three questions, in order
A raise is where most rent mistakes happen, and the order of the questions matters. First, is there a cap on this unit? Second, how much written notice does the law require? Third, does the notice have to say anything in particular? A well-written letter doesn’t make an amount lawful, and a lawful amount can still fail on the wrong notice.
Is there a cap?
Three states publish a statewide cap on increases, and they limit big jumps rather than freezing rent. As read on 5 November 2026: California 8.1% to 8.8% by area, for increases starting 1 August 2026 to 31 July 2027 (Attorney General’s chart, which calls itself informational; the rule is Civ. Code 1947.12); Oregon 9.5% for 2026 and 10% for 2027 (Department of Administrative Services); Washington 9.683% for 2026 and 10% for 2027 (Commerce, RCW 59.18.700). Washington, DC has its own rent control law, and New York City stabilized leases starting 1 October 2026 to 30 September 2027 get 0% under Order 58.
Elsewhere it gets local. In New York, New Jersey, Maryland, Minnesota and Maine, the limits we found come from particular cities or counties, or from state laws that apply only where a town opts in. Many other states, including Florida, Arizona, Colorado and Texas, bar or tightly limit local rent control. Our guide to states with rent control sorts every state by what we could read, and names the ones we couldn’t confirm.
Two things trip people up. Many units are exempt, often by building age or owner, so the cap may not reach a given unit at all. And the base matters: California measures from the lowest rent in the 12 months before the increase, not the current rent (Civ. Code 1947.12(a)(1)). The rent increase calculator asks for that lowest figure, works out the change in dollars and percent, and sets it beside the dated caps. It compares figures; it doesn’t say whether an increase is lawful.
How much notice?
There is no national notice period. In the statutes we read, California requires 30 days for a rise of 10% or less in 12 months and 90 days above that, for month-to-month and shorter tenancies (Civ. Code 827(b)). Oregon requires 90 days, or 7 for week-to-week (ORS 90.323), and Washington 90 days, with no rise before the rental term ends (RCW 59.18.140(3)). The landlord-tenant chapters we read for Texas, Florida, Arizona and Pennsylvania set no rent increase notice at all, though the lease and city rules can still apply.
What the notice has to say
In most states we read, no statute lists the contents. A few do: Washington requires a notice substantially in the form set out in RCW 59.18.720, and New York adds the state’s Good Cause notice where that law applies. Our guide to the rent increase letter has the full notice table, the items a clear letter covers, how delivery works in each state we read, and what silence from a tenant means in different states. Its sample wording shows coverage only and never replaces a required form.
Even where there is no cap, there are limits on why rent goes up. California bars a raise as retaliation for 180 days after listed tenant acts (Civ. Code 1942.5), and Texas for 6 months (Prop. Code 92.331). The federal Fair Housing Act bars different rental terms because of a protected class.
When rent is late: late fees
No national rule sets a late fee. The closest thing to a typical figure is the Consumer Financial Protection Bureau’s payment data: an average late fee of about $85 in November 2024, from a sample the agency says isn’t designed to represent all US renters (CFPB, January 2025). That is an average of fees charged, not a limit.
Of the 50 states and DC, we read a number or a waiting period in 15, a “reasonable” style test in 6 and no amount in the chapters we read for 12. The other 18 we could not confirm. The wording matters more than the percentage. New York allows the lesser of $50 or 5% of monthly rent, once rent is 5 days unpaid (RPL 238-a(2)). Texas is often called a cap but is a safe harbor: a fee in a written lease is treated as reasonable up to 12% of rent in a structure of 4 or fewer units, or 10% in a larger one (Prop. Code 92.019), and the fee can’t come before rent is 2 full days late.
Late fees also behave differently once an eviction starts. In a New York summary proceeding, no fees or charges other than rent can be sought; DC bars eviction for nonpayment of a late fee (D.C. Code 42-3505.31); Washington counts late fees only up to $75 in total. Our guide to rent late fees by state has every row we read, worked examples on $1,500 rent, and the rules on written terms, daily fees and subsidized rent.
Where rent meets the rest of the tenancy
Rent questions often turn into other ones. Money collected up front can count as part of the deposit: California treats an advance payment of rent as security under Civ. Code 1950.5(b), so a partial month plus a full month at move-in raises a deposit question, covered in our section on security deposits. Unpaid rent is the most common start of an eviction, and that has its own court process, set out in our section on eviction and squatters. Several rent rules also turn on how many units the owner has, from Texas’s late fee safe harbor to Washington’s cap exemptions, and our page on rules that change with your unit count gathers them.
Your next step
Start with the lease and find three lines: how a partial month is charged, any rent-change clause and its notice terms, and the late fee and when it starts. Then check the address, not just the state: ask the city or county whether it has a rent board or local rent rules. If your state isn’t in our tables, the state agency or the clerk of your local court can say what applies.
If a tenant has disputed a raise or a fee, a rent board has opened a case, or court papers have arrived, stop and talk to a lawyer or legal aid before the next step. Court papers carry deadlines that can’t wait.
Sources checked on 6 November 2026.
