You generally cannot wait and pay all your federal taxes at year-end without a penalty. The IRS runs a pay-as-you-go system, and if you end up owing $1,000 or more after withholding and refundable credits, it charges an interest-based underpayment penalty for every quarter you should have paid something and didn’t. There are a few narrow escapes, and one useful workaround involving paycheck withholding, but the default answer for freelancers, investors, retirees, and anyone with meaningful non-wage income is that a single April check is not enough.
Why the IRS Expects Payment Throughout the Year
Federal tax is designed to be paid as income is earned, not in one settlement at filing. For W-2 employees, that happens automatically: the employer calculates withholding from each paycheck using Form W-4 and remits it on the worker’s behalf.1Internal Revenue Service. Pay as You Go, so You Won’t Owe: A Guide to Withholding, Estimated Taxes and Ways to Avoid the Estimated Tax Penalty For income that doesn’t run through a payroll system, the IRS expects you to calculate and send quarterly estimated payments using Form 1040-ES.2Internal Revenue Service. 2026 Form 1040-ES
The four deadlines for the 2026 tax year are April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027.3Internal Revenue Service. When to Pay Estimated Tax – Individuals 2 Each period is evaluated on its own. A large payment in January doesn’t cure a missed April quarter.
When You Actually Can Pay Everything at Year-End
The rule has real exceptions. You won’t owe an underpayment penalty for 2026 if any of the following is true.
Your final tax bill after withholding and credits is under $1,000. If the amount left over when you file is less than $1,000, no penalty applies regardless of whether you made any estimated payments during the year.4Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax This is the cleanest path to a year-end-only payment: keep the balance small.
Your withholding already meets a safe harbor. The IRS treats you as paid up for the year if your total withholding and estimated payments cover at least 90% of your current-year tax, or 100% of the tax shown on your prior-year return (assuming it covered a full 12 months).5Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty If your 2025 adjusted gross income was over $150,000 (or $75,000 if you’re married filing separately), the prior-year threshold rises to 110%.6Internal Revenue Service. Publication 505 (2025), Tax Withholding and Estimated Tax Someone whose W-2 withholding alone hits one of these numbers can add a modest side income and still pay the remainder at filing without penalty.
You qualify as a farmer or fisherman. If at least two-thirds of your gross income comes from farming or fishing (in either the current or prior year), you can skip quarterly payments entirely and pay your full tax when you file, provided you file and pay by March 1 of the following year.7Internal Revenue Service. Topic No. 416, Farming and Fishing Income A single January 15 payment plus a normal April filing is the other option.
The Withholding Workaround
Here is the practical loophole for W-2 employees who also have investment income, a side business, or other non-wage earnings. Withholding is treated as paid evenly across the year regardless of when it actually came out of your paychecks. So instead of sending quarterly estimated payments, you can file a new W-4 with your employer and ask for extra withholding large enough to cover the tax on your outside income.8Internal Revenue Service. Taxpayers Should Check Their Federal Withholding to Decide if They Need to Give Their Employer a New W-4 The IRS doesn’t care whether the money arrives through withholding or estimated payments, only that it arrives on time.
Retirees can do the same thing with pensions and annuities by filing Form W-4P, and Social Security recipients can request withholding through Form W-4V.9Internal Revenue Service. Form W-4P – Withholding Certificate for Periodic Pension or Annuity Payments If you can route your tax through withholding rather than through the estimated payment system, the timing question effectively disappears.
What Skipping Quarters Actually Costs
The underpayment penalty is not a flat fine. It’s interest, charged on the amount you should have paid for each quarter but didn’t, running from that quarter’s deadline until you pay. The rate is set quarterly at the federal short-term rate plus three percentage points. For the first quarter of 2026 it is 7%, and for the second quarter it drops to 6%.10Internal Revenue Service. Quarterly Interest Rates11Internal Revenue Service. Internal Revenue Bulletin No. 2026-8
Because each quarter is evaluated separately, someone who earns $40,000 in the first quarter and pays nothing until January will get charged the applicable rate on that first-quarter underpayment for roughly nine months, even if the January check covers the entire year’s tax.5Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty You can also owe the underpayment penalty and still receive a refund: it happens when your total payments cover the year’s tax in dollar terms but weren’t spread across the four deadlines. The IRS just subtracts the penalty from what it sends back.
Self-employed workers feel this most because they owe self-employment tax on top of income tax: a combined 15.3% rate covering Social Security (12.4%) and Medicare (2.9%) on their net earnings, with no employer split.12Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) A freelancer earning $10,000 on the side can easily clear the $1,000 threshold once income tax and self-employment tax are combined.
If Your Income Really Does Arrive Late in the Year
Some income legitimately shows up in one lump. A real estate agent whose closings cluster in summer, a consultant who lands a single fall contract, or an investor with a December capital gain didn’t have first-quarter income to pay tax on. The IRS accounts for this through the annualized income installment method, which calculates each installment based on the income you actually earned through the end of each period rather than assuming equal quarters.13Internal Revenue Service. 2025 Instructions for Form 2210
To use it, attach Form 2210 with Schedule AI to your return. Once you elect Schedule AI for any period, you must use it for all four. The math is more involved, but it can lower or eliminate the required payment for quarters where you had little income, and it can substantially reduce the penalty for someone whose earnings are genuinely back-loaded.14Internal Revenue Service. Estimated Taxes
This is not the same as being allowed to pay everything at year-end. It’s a recalculation that recognizes late-year income was late-year income. If your money came in during Q1 and you held onto it, Schedule AI won’t help.
Waivers for Unusual Circumstances
The IRS can waive the underpayment penalty when the shortfall stems from a federally declared disaster, a casualty event, or another unusual circumstance that would make the penalty inequitable. It can also waive the penalty if you retired after reaching age 62 or became disabled during the tax year or the year before, and the underpayment was due to reasonable cause rather than neglect.15Internal Revenue Service. Penalty for Underpayment of Estimated Tax
These aren’t automatic. You file Form 2210 with an explanation, and the IRS evaluates each request individually.
The Short Version
If your withholding already covers 90% of this year’s tax or 100% of last year’s (110% at higher incomes), you can pay any remainder at filing with no penalty. If your total balance due comes in under $1,000, same result. If you’re a farmer or fisherman meeting the two-thirds test, you have a special March 1 track. Outside those situations, waiting until year-end means paying interest on every quarter you skipped, calculated from that quarter’s deadline forward. The cleanest fix for most people with unpredictable non-wage income isn’t to argue with the calendar; it’s either quarterly estimated payments or extra withholding through a W-4 adjustment that lets the IRS treat the money as paid on time.