A pay or quit notice is a formal written demand that gives a tenant who is behind on rent a short, fixed window to either pay the full balance owed or move out. It is usually the first legal step a landlord takes before filing for eviction, and serving it correctly is what lets the case proceed if the tenant does neither.
In practice
Say rent is $1,600, due on the 1st with a five-day grace period and a flat $50 late fee. The tenant pays nothing by the 6th, so the charge is now officially late and the fee applies, bringing the balance to $1,650. You serve a pay or quit notice that states the exact amount due, $1,650, the deadline to cure it, and the method of delivery. If the notice gives the tenant a certain number of days to pay and they hand you $1,650 inside that window, the matter is closed and the tenancy continues. If the window passes with nothing paid, you have the documented basis to file the next step in court.
The number of days you must give varies widely by state, commonly three, five, or ten, and so do the rules for how the notice may be delivered and whether weekends and holidays count. Do not assume a universal number. Read your state's statute and follow the service method it names, because a notice served the wrong way can get the whole case thrown out on the first hearing.
Why it matters to a small landlord
The notice is the hinge between an informal collection problem and a legal one, and the math on it has to be exact. If you demand the wrong amount, name the wrong deadline, or skip the delivery method your statute requires, a judge can dismiss your filing and send you back to the start, weeks behind. You generally cannot even serve the notice until rent is truly past due, which means after any grace period has run, so the first thing to get right is the date the balance becomes late. Treat the notice as the top rung of a documented escalation, not a surprise. A written late rent escalation that moves from a friendly reminder to a formal demand gives you a clean paper trail and often gets the rent paid before court is ever on the table.
The notice rarely stands alone. If the deadline passes unpaid, it typically becomes the predicate for an unlawful detainer, the actual eviction lawsuit, so the figures on the two documents must agree. The amount you demand should tie back to the recorded charge plus any late fee your lease allows, with nothing improvised. Get the dates and dollars right on the first notice and the rest of the process has far less to argue about.