Last updated: October 2026

Underpayment Penalty Rules for Employers and Individuals

The underpayment penalty hits employers who miss deposits and individuals short on estimated tax. Employer deposit penalties run off Internal Revenue Code (IRC) Section 6656 as a federal tax deposit (FTD) penalty, on the four tier ladder set out below. Individual filers face a separate rule that runs through Form 2210, with two safe harbor tests.

Two Underpayment Penalty Paths

Each is a separate assessment with its own trigger, its own math, and its own cure.

The individual side applies when you owe $1,000 or more at filing and did not pay enough through withholding or quarterly estimates. The Internal Revenue Service (IRS) figures the penalty on each installment’s shortfall for the number of days it stays unpaid. The rate is the published quarterly underpayment rate, which is the federal short-term rate plus three percentage points. That math sits inside Form 2210. The form also carries the two safe harbors that stop the assessment before it starts.

Employers face a different trigger. The penalty applies when a federal tax deposit is late, short, or not made the right way. IRC Section 6656 sets it as a percentage of the unpaid deposit, and the rate climbs with the number of calendar days late. Publication 15 spells out the deposit schedule, but the penalty math sits in the statute.

Form 2210 covers individuals, estates, and trusts, so it does nothing for a missed payroll deposit. The business owes the deposit penalty under 6656, while the owner separately owes the Form 2210 assessment on personal return shortfalls.

Employer FTD Penalty Tiers Under IRC Section 6656

The failure to deposit penalty has four tiers, counted in calendar days from the due date. One to five days late costs 2% of the unpaid deposit. Six to fifteen days costs 5%. Sixteen or more days late costs 10%.

If the deposit is still unpaid more than 10 days after the date of the first IRS notice, the rate jumps to 15%. The same 15% applies on the day you get a notice demanding immediate payment. The tiers do not add up: a deposit more than 15 days late owes 10% in total, not 10% on top of 2% and 5%. A single $25,000 deposit that reaches the 15% tier costs $3,750 in penalties alone.

The IRS also charges interest on the penalty, compounded daily, at the federal short-term rate plus three percentage points. For October through December 2026, that underpayment rate is 7%.

Publication 15 also sets a deposit shortfall safe harbor. No penalty applies if the shortfall does not exceed the greater of $100 or 2% of the required deposit, and you make it up on time. A monthly depositor makes up the shortfall by the due date of the return, and may pay it with the return. A semi-weekly depositor deposits it by the first Wednesday or Friday on or after the 15th of the following month. If the return is due sooner, the return due date controls.

Under the 2026 Publication 15, the Electronic Federal Tax Payment System (EFTPS) accepts same-day payments of $1 million or less submitted before 3 p.m. Eastern time on a business day. A payment over $1 million must be submitted by 8 p.m. Eastern time the day before it is due. A third party making the deposit for you may have different cutoff times. A deposit due on a Saturday, Sunday, or legal holiday is timely if made by the close of the next business day.

How Depositor Status Controls Your Filing Cadence

Every employer is a monthly depositor or a semi-weekly depositor. The schedule follows from a lookback period covering the four quarters ending June 30 of the prior year. Reporting $50,000 or less of taxes in that window makes you a monthly depositor. More than $50,000 makes you a semi-weekly depositor.

For 2026 deposits, the lookback period runs July 1, 2024 through June 30, 2025.

Monthly depositors send each month’s taxes by the 15th of the following month. Semi-weekly depositors follow the Wednesday or Friday rule. Taxes on Wednesday, Thursday, and Friday pay dates are due the following Wednesday. Taxes on Saturday through Tuesday pay dates are due the following Friday. If a legal holiday falls in the 3 weekdays after a semi-weekly period, you get one more day for each holiday.

Every employer can hit the $100,000 next-day deposit rule. Accumulate $100,000 or more in taxes on any day during a deposit period, and the tax is due by the next business day. A monthly depositor who hits it becomes a semi-weekly depositor the next day, for the rest of that year and the following year.

Schedule B attaches to Form 941 for every semi-weekly depositor. It reports tax liabilities, not deposits, on the lines for the dates employees were paid. Form 945 handles nonpayroll withholding like backup withholding and certain pension distributions. Those deposits are made separately from payroll deposits.

New employers are monthly depositors for the first calendar year of the business, because their lookback liability counts as zero.

Form 2210 Safe Harbors for Individual Filers

Two safe harbor tests provide the exit route. Option one: pay 90% of your current year tax through withholding and timely estimated payments. Option two: pay 100% of last year’s tax, or 110% if last year’s adjusted gross income (AGI) was over $150,000 ($75,000 if married filing separately).

The safe harbor calculation does not care whether you end up owing $50 or $50,000 at filing.

Quarterly installment dates are April 15, June 15, September 15, and January 15 of next year. The penalty is figured separately for each installment date, so a later payment may not erase an earlier shortfall. Pay by January 15 to keep the safe harbor intact, and final Form 1040 filing by April 15 closes the loop.

Form 2210 also contains the annualized income installment method. It matters for filers with uneven income, such as consultants who earn most fees in the fourth quarter, freelancers on project cycles, and commission earners with seasonal payouts. Instead of dividing the year into four equal quarters, you figure tax on the income actually earned through the end of each period.

The annualized method can reduce the penalty on a quarter where you earned nothing. The tradeoff is filing complexity: using it means attaching Form 2210 and Schedule AI (Annualized Income Installment Method) to your return.

Not every filer owes a Form 2210 attachment.

The IRS will generally figure the penalty and send a bill. You must file the form in some situations, such as a waiver request or the annualized method.

Reasonable Cause and First-Time Abatement Through Form 843

Two separate abatement paths exist, and the paperwork is similar but the standard is different. First-Time Abatement (FTA) is administrative relief for taxpayers with a history of timely compliance. Reasonable cause relief requires showing you used ordinary care and prudence and still could not meet the deadline.

The IRS is moving FTA to a new Automatic Exemption from Penalty (AEP), starting summer 2026. AEP covers Forms 940, 941, 943, 944, and 945, starting with 2026 quarterly returns. If IRS records show three years, or 12 consecutive quarters, of timely compliance, the deposit penalty is not assessed. The IRS sends a notice explaining the relief, and you do not need to contact it.

FTA still covers earlier periods and any 2026 quarterly return not considered for AEP. It is not automatic: you must contact the IRS, and the penalty is assessed first, then removed.

Both forms of relief require a timely compliance history. The same return type must have been filed on time for the prior three years, or 12 consecutive quarters. No penalty other than the estimated tax penalty can have been assessed in that window, unless it was later abated for reasonable cause or IRS error. Businesses face two more tests. The IRS must not have waived the deposit penalty four or more times in those three years, and the penalty cannot stem from avoiding EFTPS.

Reasonable cause requires a specific story. IRS examples of valid reasons include fires, natural disasters, inability to get records, and death or serious illness. System issues that delayed a timely electronic payment can also qualify. Lack of funds, by itself, is not reasonable cause. Mistakes, oversights, and reliance on a tax professional generally do not qualify either. Hospital or court records, or a doctor’s letter with start and end dates, can confirm an illness.

Form 843 is the written request vehicle for both. Explain what happened and when, how it kept you from depositing on time, and what you tried. If you are answering an IRS notice, mail the form to the return address on that notice.

You can also ask by phone at the toll-free number in the top right corner of your notice. For FTA, you do not need to name it or send documents; the IRS checks your account for eligibility.

Common Deposit Mistake Patterns That Compound the Assessment

Three deposit patterns produce 6656 assessments.

Semi-weekly status misread as monthly is number one. A company whose lookback total passes $50,000 is a semi-weekly depositor for the whole calendar year, so a monthly deposit lands after the due date.

Number two is the $100,000 next-day rule ignored on a large bonus run or a quarterly commission pool.

Misapplied deposits are number three. Deposits are generally applied to the most recent tax liability within the quarter. After a deposit penalty notice, you have 90 days from the notice date to designate how deposits apply, which can lower the penalty.

Before Your Next Quarterly Deposit

Verify Schedule B accuracy if you are semi-weekly. Load each pay-period deposit into EFTPS at least one business day ahead of your due date.

For individuals, calculate both safe harbors on a blank sheet. Take the tax shown on last year’s return, multiply by 1.00 or 1.10 depending on AGI, divide by four, and set a calendar reminder for each installment date. If current-year income is volatile, commit to the annualized method early.

Start with our payroll tax penalties breakdown for the stacking math. Review Form 941 filing rules if you are not sure about Schedule B. Confirm current-year rates and wage bases on the 2026 payroll tax rates page before setting your next estimate. For 2027, see the 2027 payroll tax rates. IRS failure to deposit penalty guidance spells out the tier structure directly, and the payroll tax hub covers the remainder of your quarterly compliance calendar.

This is not legal or financial advice. Consult a qualified professional for your specific situation.