After every payroll, an employer owes the IRS the federal income tax withheld plus both halves of Social Security and Medicare. When you have to hand that money over — and it is a real deadline with real penalties — depends on your deposit schedule. Most employers are on one of two: monthly or semi-weekly. Here is how the IRS decides which one applies to you, and the two thresholds that can override it.
This is general information, not tax advice. Confirm your own classification against your IRS notices.
The lookback rule sets your schedule
You do not pick your deposit schedule — it is assigned based on how much employment tax you reported during a "lookback period." For 941 filers, the lookback is the four quarters ending June 30 of the prior year (July 1 through June 30).
If your total employment tax in that lookback period was $50,000 or less, you are a monthly depositor for the coming year. If it was more than $50,000, you are a semi-weekly depositor. The schedule is set for the whole calendar year — it does not flip back and forth as your payroll changes month to month.
New employers with no lookback history are monthly depositors by default for their first calendar year.
What each schedule means for due dates
Monthly depositors deposit the tax for all paydays in a month by the 15th of the following month. Simple and predictable.
Semi-weekly depositors follow the payday: taxes for paydays on Wednesday, Thursday, or Friday are due the following Wednesday; taxes for paydays on Saturday, Sunday, Monday, or Tuesday are due the following Friday. The name refers to the deposit rhythm, not to being paid twice a week.
The $2,500 rule: you may not need to deposit at all
If your total employment tax for the quarter is less than $2,500, you can skip deposits entirely and pay the balance with your quarterly return. This is a per-quarter, based on your actual current liability — a genuine convenience for very small employers.
The $100,000 one-day rule: the one that catches people
This is the exception that overrides everything else. If you accumulate $100,000 or more in employment tax liability on any single day, that deposit is due by the next business day — even if you are normally a monthly depositor. A large one-time payroll (big bonuses, a stock event, a final payout) can trigger it without warning.
And it does not stop there: once you hit the $100,000 one-day rule, you immediately become a semi-weekly depositor for the rest of the year and the entire next year. It is one of the most common ways employers get hit with a failure-to-deposit penalty, because the liability is measured on the day it accrues, not at the end of the period.
When your schedule changes
Your base schedule is recalculated once a year from the new lookback period, so it can shift from monthly to semi-weekly (or back) at the start of a calendar year. The $100,000 rule can also flip you to semi-weekly mid-year. Because the classification drives Form 941, Part 2 and every deposit due date, it is worth confirming each year and after any unusually large payroll.
How Payrollix handles it
Payrollix classifies each company automatically from the IRS lookback, applies the $2,500 de-minimis and the $100,000 one-day rule, and schedules every federal deposit on the correct due date — rolling forward over weekends and banking holidays. If you take over a client mid-year and their prior-year liability would make them semi-weekly, you can also set the classification directly rather than wait for the lookback to catch up. The goal is that the right amount lands with the IRS on the right day, without you tracking deposit calendars by hand.
See what flat per-client pricing looks like
Start your 14-day free trial. No credit card required.
Start Free Trial