Estimated Tax Safe Harbor Rules for High Earners in 2026

The short answer: if your 2025 adjusted gross income was more than $150,000, you can generally avoid a federal underpayment penalty for 2026 by paying in, through withholding and estimated payments, at least 110% of the total tax on your 2025 return, spread across the four due dates. You can instead pay 90% of your actual 2026 tax, whichever is smaller. If your income arrives unevenly, the annualized income installment method can lower the payments due early in the year.

For business owners and high earners, these rules matter because most of your income isn’t subject to regular withholding. Here is how each option works, the 2026 dates, how withholding counts, and how Oklahoma’s rules differ.

Who has to make estimated payments

Under the 2026 Form 1040-ES instructions, you generally must pay estimated tax if both of these apply:

• You expect to owe at least $1,000 for 2026 after subtracting your withholding and refundable credits.
• You expect your withholding and refundable credits to be less than the smaller of 90% of your 2026 tax or 100% of your 2025 tax (110% for higher-income taxpayers, below).

That describes most owners of S corporations, partnerships, and sole proprietorships, plus investors with large dividends, capital gains, or rental income. If you had no tax liability for all of 2025 and were a U.S. citizen or resident all year, you don’t have to pay estimated tax for 2026.

The safe harbors for high earners

Think of the safe harbors as targets. Hit any one of them on time, and you avoid the federal underpayment penalty even if you still owe a balance when you file.

1. The 110% prior-year safe harbor

If your 2025 AGI was more than $150,000 ($75,000 if your 2026 filing status is married filing separately), the prior-year target is 110% of the total tax on your 2025 return, instead of 100%. Your 2025 return must cover a full 12 months.

This is usually the easiest target for a growing business, because the number is known the day you file last year’s return. Your 2026 profit can rise sharply and you still avoid the penalty, though you will owe the difference when you file.

2. The 90% current-year option

You can instead pay 90% of the tax you will actually owe for 2026. This works better when you expect 2026 income to be lower than 2025. The catch is that you don’t know the final number until the year is over, so it relies on a good projection. Guess low, and you may owe a penalty for one or more quarters.

3. The annualized income installment method

The first two options assume four equal payments. If your income is uneven, such as a large capital gain in the fall, a seasonal business, or a big year-end bonus, the annualized income installment method lets each payment match the income you actually earned through the end of that period. That can lower or eliminate the earlier payments. If you use it, you file Form 2210 with Schedule AI with your return, even if no penalty is owed.

Here is a hypothetical example. An owner’s 2025 return showed total tax of $200,000, and 2025 AGI was well over $150,000. The 110% target for 2026 is $220,000, or $55,000 a quarter. If the owner projects $300,000 of 2026 tax, 90% of that is $270,000. The smaller target, $220,000, is the safe harbor. Paying $55,000 by each due date avoids the penalty; the remaining $80,000 is due with the 2026 return.

2026 due dates

For calendar-year individuals, the 2026 federal estimated tax payments are due:

You don’t have to make the January 15, 2027 payment if you file your 2026 return by February 1, 2027 and pay the full balance with it. For most business owners waiting on K-1s, that isn’t practical, so plan on the January payment.

The penalty is figured separately for each payment period. A large January payment doesn’t erase an underpayment from April or June. If your income jumps midyear and you raise your payments, you may still owe a penalty for the earlier periods unless the annualized method covers them.

Farmers have their own rule. If at least two-thirds of your gross income for 2025 or 2026 is from farming or fishing, the 90% figure becomes 66⅔%, the 110% rule doesn’t apply, and you can either pay all your estimated tax by January 15, 2027, or file and pay in full by March 1, 2027.

How withholding counts

Withholding gets special treatment. For penalty purposes, federal income tax withheld is treated as paid in four equal amounts on the four due dates, unless you choose to show the dates it was actually withheld. Estimated payments, by contrast, count on the day you make them.

That difference gives high earners a useful tool. If you are behind in December, extra withholding from wages, including an S corporation owner’s own salary, is spread back across the whole year, which can cover shortfalls in earlier quarters. A late estimated payment can’t do that.

For S corporation owners, this ties into how you set your salary. Our guides to the S corp election and the tax planning calendar cover how payroll and year-end timing fit together.

Oklahoma estimated payments

Oklahoma has its own rules, and they aren’t the same as the federal ones. According to the Oklahoma Tax Commission’s 2026 Form OW-8-ES and its resident return instructions:

• Who pays: you must make quarterly estimated payments if you expect your Oklahoma tax to exceed your withholding by $500 or more.
• The target: withholding and timely estimated payments must equal the smaller of 70% of your current-year Oklahoma tax or 100% of your prior-year Oklahoma tax. The Oklahoma instructions don’t include a separate 110% rule for higher incomes.
• The cost of missing it: Oklahoma charges underpayment interest at 20% a year for the period of underpayment. No underpayment interest applies if the tax shown on your return is less than $1,000.
• Due dates: April 15, June 15, September 15, and January 15 of the following year, moved to the next business day when a date falls on a weekend or holiday.
• Uneven income: Oklahoma also allows the annualized income installment method.
• Farmers: if at least two-thirds of your gross income for this year or last year is from farming, Oklahoma estimated payments aren’t required.

Payments can be made online through OkTAP or with the Form OW-8-ES coupon.

If your S corporation or partnership has made the Oklahoma PTE election, the business makes its own Oklahoma estimated payments on Form OW-8-ESPTE when its estimated liability is $500 or more. Those are business-level payments, separate from your personal federal and Oklahoma estimates. Track them separately so neither one is double counted or missed.

How we help

At Cannon & Brown Tax Advisors, we set your federal and Oklahoma estimates as part of your tax plan, check them against your real numbers each quarter, and keep your personal payments and any business-level PTE payments in separate columns. Our technology keeps those projections current, and your tax strategist reviews every number. If you’d like a clear picture of what you should be paying in, start with a free tax analysis.

Illustrative example. The people and figures in this article are hypothetical, used to explain how the rules work. They are not a client and not a promise of results.

This article is educational and is not tax advice for your situation. Tax law may change, which may change these rules and numbers.

Sources

• IRS: 2026 Form 1040-ES, Estimated Tax for Individuals
• IRS: Publication 505 (2026), Tax Withholding and Estimated Tax
• IRS: Instructions for Form 2210
• Oklahoma Tax Commission: 2026 Form OW-8-ES, Individual Estimated Tax
• Oklahoma Tax Commission: 2025 Form 511 Resident Income Tax Instructions
• Oklahoma Tax Commission: 2026 Form OW-8-ESPTE, Electing Pass-Through Entities Estimated Tax