Tax planning

Q4 Estimated Taxes Due January 15, 2027: What to Do

Updated October 1, 2026

The last estimated payment for 2026 is due January 15, 2027. You can generally avoid the underpayment penalty by paying at least 90% of this year's tax or 100% of last year's tax, whichever is smaller.

The date and the rule

Estimated tax is paid in four installments for the year. The 2026 due dates are April 15, June 15 and September 15 of 2026, and January 15, 2027. The fourth one, for the last months of 2026, is due January 15, 2027. That is a Friday and not a federal holiday, so no shift applies. The IRS says that if a due date falls on a Saturday, Sunday or legal holiday, a payment is on time if made the next day that is not one of those.

If you mail a payment, the IRS says the date of the U.S. postmark is the date of payment. You can also pay online with IRS Direct Pay, by phone, or with the IRS2Go app. Do not wait until the last day if you can avoid it.

The payment periods do not match the calendar quarters exactly, and the last one arrives after the year has ended. The January payment is still counted for 2026, not 2027. Label it clearly when you pay.

Who has to pay

The IRS says individuals generally have to make estimated tax payments if they expect to owe $1,000 or more when their return is filed. That covers many self-employed people, freelancers, landlords, and anyone with sizable income that has no withholding. Read our estimated taxes overview for the whole year.

If your income changed a lot this year, do not rely on the earlier payments you set at the start of the year. Rework the estimate now. A one-time large payment or a slow quarter can change what you should send in January.

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Safe harbor: how to avoid the penalty

The IRS says most taxpayers will avoid the underpayment penalty if they owe less than $1,000 after withholding and credits, or if they paid at least 90% of the tax for the current year, or 100% of the tax shown on the prior year's return, whichever is smaller.

There is an extra rule for higher earners. The Form 1040-ES instructions say that if your adjusted gross income (AGI) on your 2025 return was more than $150,000 ($75,000 if your filing status for 2026 is married filing separately), you use 110% instead of 100% of last year's tax for the prior-year test. Check your own 2025 AGI before you rely on the 100% test.

Pay 90% of this year's tax, or
Pay 100% of last year's tax (110% for higher income), whichever is smaller.

The two tests give you options. If your income jumped this year, the prior-year test may be easier because it does not depend on what you earn now. If your income fell, the 90% test may be the smaller number and save you cash.

How to calculate it roughly

This is a made-up example with round numbers, not a quote and not your numbers. Say your total tax on last year's return was $12,000, and your AGI last year was $150,000 or less, so the 100% test applies. The 100% safe harbor is $12,000, or $3,000 per payment across four payments. If you paid $3,000 in April, June and September, your fourth payment under that method is $3,000.

Now say this year is better than expected and you think your tax will reach $20,000. The 90% test gives $18,000. The smaller number, $12,000, is your safe harbor, so the plan above still avoids the penalty. You might still owe the difference when you file, so set money aside for it.

Find last year's total tax on your return.
Add up what you have already paid this year.
Subtract to see what is left for the fourth payment.
Compare with 90% of your expected 2026 tax.

If your income is uneven, the payments may not have to be equal. Some people pay more in the quarters when they earn more. If you want a refresher on how the four payments fit together, see our tax deadlines guide.

What happens if you miss it

The IRS says that if you did not pay enough tax through withholding or estimated payments during the year, you may have to pay a penalty for underpayment of estimated tax. It is not a reason to panic. Make the payment as soon as you can, because the penalty is figured by how much and how long the amount was underpaid. If you get a notice, our back taxes guide explains general options, but we do not represent you before the IRS or set up payment plans. A qualified professional who does representation can help.

One more point. Paying late is still better than never paying. If you cannot afford the whole amount, pay what you can and talk to a qualified professional about your options.

What to gather

Before you pay, gather last year's return, a profit and loss report through year end, your payment dates and amounts so far, and any other income with withholding. Use the quote calculator if you are thinking about return prep for 2026.

Also keep proof that you paid, such as a confirmation number or a bank record. When your return is prepared, the payments are entered by date and amount, and mistakes here can lead to the wrong balance due.

A short plan for the next few weeks

You have time before January. Use it.

By early October, review what you have paid so far against last year's tax.
By November, update your profit estimate with actual numbers.
In December, decide the amount for the January payment.
Pay a few days early so a slow weekend or a website problem does not cause a miss.
Save the confirmation for your records.

If you are also weighing other year-end moves, read our year-end planning checklist.

FAQ

What is the Q4 estimated tax due date for 2026?

It is January 15, 2027. If a due date lands on a weekend or holiday, the IRS accepts a payment made on the next business day.

Do I have to pay the January payment if I file early?

Not always. The IRS says you do not have to make the January 15, 2027 payment if you file your 2026 return by February 1, 2027, and pay the entire balance due with the return. Otherwise, make the payment by the due date, and use your return to true up what you owe or are owed.

What is the safe harbor?

The IRS says most taxpayers avoid the penalty if they paid at least 90% of this year's tax or 100% of last year's tax, whichever is smaller. Higher earners may have a 110% test.

Can I pay more than I owe?

Yes. Extra payments count toward your total tax for the year, and any overpayment is refunded or credited when you file.

Sources

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General information, not tax advice for your specific situation. Rules can change, and a human preparer reviews your facts before any return is filed. Zero Fuss Taxes is a PTIN-holding tax preparation firm. We are not a CPA firm, enrolled agents or attorneys.

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