Estimated Tax Deadlines and Penalties

Who must pay estimated tax, the four payment dates for 2026, the rules that let you avoid an underpayment penalty, and what late filing and late payment cost.

Last updated: October 12, 2026. Who must pay, the safe harbors, the penalty rates and the $525 minimum failure-to-file penalty were checked against IRS Topic 306, Topic 653 and the IRS estimated taxes page on that date. The four due dates are the standard calendar dates used by the quarterly estimator; the IRS estimated taxes page does not print them, so confirm them in Form 1040-ES.

Who has to pay estimated tax

The US tax system is pay-as-you-go. The IRS says taxes must be paid as you earn or receive income during the year, either through withholding or through estimated payments. An employee's paycheck handles this automatically. A freelancer, sole proprietor, partner or S corporation shareholder has no employer withholding, so the IRS expects quarterly payments if you expect to owe $1,000 or more when you file. You may also need to pay if you owed tax last year. You generally do not need to pay for the current year if you had no tax liability for the prior year, were a US citizen or resident for the whole year, and your prior year covered 12 months.

People with a job and a side business have a choice. They can make estimated payments, or they can raise the withholding on their paycheck by filing a new Form W-4, because withholding is treated as paid evenly throughout the year even if the extra amount is withheld late. Many people find that easier than remembering four dates.

The four due dates for tax year 2026

The "quarters" are uneven: the second covers two months, the third three months and the fourth four. If a due date falls on a weekend or a legal holiday, you can pay on the next business day. For a mailed payment, the US postmark date counts as the payment date. You can also pay weekly, biweekly or monthly as long as you have paid enough by the end of each period.

As of this page's update date in October 2026, the first three payments for 2026 have already passed. If you missed them, paying now still helps: the underpayment penalty is calculated for each period, from the due date until the amount is paid, so a late payment costs less than no payment.

How to pay

The IRS accepts payments by mail with a Form 1040-ES voucher, online, by phone, through the IRS app, or from your online account at IRS.gov/account. Paying electronically gives you a confirmation and avoids mail delays. Keep every confirmation, because you will need the total of your payments when you file your return.

The safe harbor rules: how much is enough

You do not need to guess your tax to the dollar. According to IRS Topic 306, you generally avoid the underpayment penalty if you owe less than $1,000 after subtracting withholding and refundable credits, or if your withholding and estimated payments total at least 90% of this year's tax or 100% of the tax shown on last year's return, whichever is smaller. The IRS notes that higher-income taxpayers have special rules described in Form 1040-ES. The quarterly estimator treats prior-year adjusted gross income above $150,000 as the higher-income case and uses 110% of last year's tax; confirm that threshold in the Form 1040-ES instructions for your year.

Example. Suppose you expect to owe $19,176 for the year, as in the $90,000 freelancer example, and last year's total tax was $12,000 with adjusted gross income of $80,000. Ninety percent of this year's estimate is $17,258. Last year's tax is $12,000. The smaller is $12,000, so paying $3,000 each quarter protects you from the penalty, even though you will owe the remaining balance of about $7,176 when you file. A freelancer with a growing income can use this to keep cash in the business during the year, but needs to have the balance ready in April. A higher-income taxpayer whose prior-year income was above the threshold would compare 90% of this year with 110% of last year instead.

Payments are expected in four equal amounts. If your income is uneven, such as a seasonal business or a big sale in December, the annualized installment method on Form 2210 lets you match payments to when income arrived, and the penalty may be reduced or avoided.

The underpayment penalty

If you do not pay enough by a due date, you may owe a penalty even if you are due a refund when you file. IRS Topic 306 points to Form 2210 to find out whether you owe the penalty and how much. The penalty is built from the amount underpaid in each period, the number of days it was unpaid and the interest rate in effect. The IRS may waive it if a casualty, disaster or other unusual circumstance kept you from paying and the penalty would be inequitable, or if you retired after age 62 or became disabled during the year or the prior year and the underpayment was due to reasonable cause.

Late filing and late payment penalties

These are separate from the underpayment penalty and apply to the balance due when you file. According to IRS Topic 653:

• The failure-to-file penalty is usually 5% of the tax owed for each month or part of a month that the return is late, up to 25%. If the return is more than 60 days late, a minimum penalty applies, which for returns due in 2026 is the lesser of $525 or 100% of the tax owed.
• The failure-to-pay penalty is 0.5% of the unpaid tax per month or part of a month, up to 25%. It rises to 1% if the tax remains unpaid 10 days after the IRS issues a notice of intent to levy, and drops to 0.25% for months when an installment agreement is in effect, if you filed on time.
• Interest accrues on unpaid tax from the due date until it is paid. The rate is set quarterly at the federal short-term rate plus 3 percentage points and compounds daily. The IRS generally does not abate interest.

The practical lesson is to file on time even if you cannot pay. The failure-to-file rate is ten times the failure-to-pay rate (5% against 0.5% per month), so filing and paying what you can limits the damage. Payments are applied first to tax, then to penalties, then to interest. You may qualify for First Time Abate, or for relief for reasonable cause, if you act in good faith and pay as soon as possible.

Related: the quarterly estimator and the common mistakes guide.