What a CP136 is
A CP136 is the IRS telling a business which federal tax deposit schedule applies to it for the next calendar year. The IRS's own opening: "Your deposit requirements for your Form 941, Employer's Quarterly Federal Tax Return, filings for next year may be different from your requirements for last year."
It is generated automatically, it arrives in the autumn, and it is based entirely on figures the business itself reported. There is no judgment in it and nothing to agree or disagree with — the only thing to check is whether the figures it used are the figures you filed.
The reason it exists is that employment tax is not paid, it is deposited, on a rhythm set by how big the business was a year and a half ago. That rhythm changes without warning and the notice is the warning.
How the schedule is decided
The IRS looks at what you reported over four quarters ending on 30 June, and compares it to $50,000. Notice 931, the IRS's own deposit-rules publication:
"Your deposit schedule for a calendar year is determined from the total tax liability reported on your Forms 941 in a 4-quarter lookback period. Your total tax liability is the amount you reported on line 12 of Forms 941. The lookback period begins July 1 and ends June 30 ... If you reported $50,000 or less of tax liability for the lookback period, you're a monthly schedule depositor; if you reported more than $50,000, you're a semiweekly schedule depositor." — IRS Notice 931 (Rev. September 2025)
The lookback is not last year. It is the four quarters ending 30 June of the previous year, which means a 2026 schedule was decided by payroll run between 1 July 2024 and 30 June 2025. A business that grew in the last twelve months is often still on the smaller schedule, and a business that shrank is often still on the larger one.
What each schedule actually requires:
| Schedule | When the deposit is due | Set by |
|---|---|---|
| Monthly | deposit accumulated taxes on payments made during a calendar month by the 15th day of the following month | $50,000 or less in the lookback |
| Semiweekly — payday Wed, Thu or Fri | by the following Wednesday | more than $50,000 in the lookback |
| Semiweekly — payday Sat, Sun, Mon or Tue | by the following Friday | more than $50,000 in the lookback |
Semiweekly depositors get at least three business days after the close of the period, and an extra business day for each legal holiday inside them.
Source: IRS Notice 931 (Rev. September 2025), and IRS, "Understanding your CP136 notice," both read 6 September 2026.
The zero in the table
If any quarter in the lookback table shows zero, the IRS is not telling you that quarter was quiet. It is telling you it never received that return. Its own page says so:
"If the tax amount we used is zero for any tax period, then we have no record of receiving Form 941 for that period. Please file any missing Form 941 as soon as possible."
That single sentence turns an informational notice into an unfiled-return warning, and it is printed inside a table most people scan for the total. An unfiled 941 does not sit still: it produces its own notice, it can produce a return prepared by the IRS, and while it is outstanding it blocks most of the arrangements a business would want if a balance ever appeared.
A zero can also be legitimate — a quarter with no wages paid, or wages reported on a Form 943 or 944 instead. The point is that only you can tell which, and the notice will not.
If a return really is missing: CP259, the business non-filer notice →
The $100,000 rule, and the half of it that never gets quoted
Accumulating $100,000 of liability on a single day means depositing it by the next business day — and, if you were a monthly depositor, it changes your schedule for at least the rest of that calendar year and all of the following one.
"If you accumulate a tax liability of $100,000 or more on any day during a deposit period, you must deposit the tax by the close of the next business day, whether you're a monthly or semiweekly schedule depositor."
"If you're a monthly schedule depositor and accumulate a $100,000 tax liability on any day during the deposit period, you become a semiweekly schedule depositor on the next day and remain so for at least the rest of the calendar year and for the following calendar year." — IRS Notice 931 (Rev. September 2025)
The second paragraph is the one that is almost always cut, and it is the larger consequence. One bonus round, one sale, one set of severance payments, and a business is on the semiweekly rhythm through the end of next year.
One more clause that decides who is caught: the threshold "is determined before you consider any reduction of your liability for nonrefundable credits." A business that netted credits against its liability and concluded it was under the line was not.
A word on what this threshold is not. It is accumulated tax liability in a deposit period — withheld income tax plus both halves of FICA — not gross payroll. The payroll that produces $100,000 of liability is a good deal larger than $100,000.
What happens if you do nothing
Nothing happens on the notice. Something happens to every deposit you make after 1 January.
If the schedule changed and the payroll routine did not, each deposit is late by the difference between the two rhythms — often a couple of weeks. The IRS's deposit penalty is a ladder, and it is charged on the underpayment for each failure:
| Rate | Charged for |
|---|---|
| 2% | Deposits made 1 to 5 days late |
| 5% | Deposits made 6 to 15 days late |
| 10% | Deposits made 16 or more days late, but before 10 days from the first IRS notice asking for the tax |
| 10% | Amounts that should have been deposited but were paid directly to the IRS, or paid with the return — subject to the "payment with return" exceptions in Publication 15 |
| 15% | Amounts still unpaid more than 10 days after that first notice, or after notice and demand for immediate payment, whichever is earlier |
The rates are not cumulative — one applies per failure — and they are percentages of the amount that was late, not of your whole payroll. But they recur on every deposit until somebody notices, and on a semiweekly schedule that is roughly twice a week.
The other thing that quietly follows a schedule change: the liability schedule filed with the return changes too. A semiweekly depositor files Schedule B with day-by-day liabilities rather than monthly totals, and getting that wrong has its own notice and its own consequence. CP207, when the liability schedule is missing or wrong →
