Quarterly estimated taxes for self-employed contractors

Self-employed contractors generally pay federal income and self-employment taxes during the year through estimated payments, unless withholding covers the required amount. Use the IRS worksheet to calculate the payments and put each due date on your calendar.

The IRS treats income tax as pay-as-you-go. It wants the money roughly as you earn it, not in one payment the following spring.

General business guidance, not tax advice. Rules and figures change. Verify anything specific against the current Form 1040-ES instructions, IRS Publication 505, or a CPA who works with contractors.

Estimated payments cover income and self-employment taxes

An employee has income tax, Social Security and Medicare taken out of every check, and the employer pays half of the Social Security and Medicare. Working for yourself, you owe both halves. That is self-employment tax, and it sits on top of ordinary income tax on the same profit.

The self-employment tax rate is 15.3% — 12.4% Social Security plus 2.9% Medicare. Under the regular method, Schedule SE generally applies it to 92.35% of net profit. Wages from another job count toward the Social Security limit too. The Social Security portion stops at an annual wage base ($184,500 for 2026, reset every year). The Medicare portion is uncapped, and an extra Medicare surtax kicks in at higher incomes.

If you are a sole proprietor or a single-member LLC taxed as a sole proprietor, estimated payments are personal. They go under your Social Security number against your Form 1040, not under the business EIN. If you elected S corporation treatment, some of your income should be coming through payroll with real withholding, which changes the arithmetic — ask your accountant.

A 1099-NEC reports certain business payments for your services. Usually no tax is withheld, though backup withholding can apply. Homeowners paying for personal work generally have no 1099 reporting duty; those payments are still business income to you.

The four dates are not quarters

This is the part that catches people. The periods are uneven, and only the first is a real calendar quarter.

Those are the IRS's own payment periods. The second is two months long. The fourth is four months and lands after New Year. Set reminders for the ends of March, June, September and December and three of the four will be wrong.

A due date that lands on a weekend or legal holiday moves to the next business day, so read the current year's four dates in Publication 505 each January and put those in your phone. You may also skip the January installment if you file the return and pay the whole balance by January 31 — a date that shifts the same way.

Pay through your IRS Online Account, Direct Pay, or EFTPS, which needs enrolling ahead of time. Mailed 1040-ES vouchers still work. Save every confirmation: the return asks for all four amounts and dates.

Safe harbors set how much you must pay on time

A safe harbor can protect you from an estimated-tax underpayment penalty even if your final tax is higher. You must meet the required installment amounts on time; reaching the annual total in December does not erase an April shortfall.

Per the Form 2210 instructions and IRS Topic 306, you generally avoid the underpayment penalty by making timely payments and withholding totaling the smaller of:

• 90% of the tax you end up owing this year, or
• 100% of the tax shown on last year's return — 110% if last year's adjusted gross income was over $150,000 ($75,000 if you file married filing separately).

There is a small-balance exception too: no penalty if your total tax minus withholding and refundable credits comes to less than $1,000. That test looks at withholding, not at estimated payments you made.

The prior-year method requires a return covering a full 12 months. Use the worksheet's definition of prior-year tax, apply 100% or 110%, and account for expected withholding before dividing the remaining required amount into installments. Pay any balance by the return's payment deadline. A separate exception may apply if you had no prior-year tax liability, were a U.S. citizen or resident all year, and that year covered 12 months.

Sizing it in a year with no prior return

Your first year in business may still have a usable prior-year personal return, including tax from employment. If the prior-year method is unavailable, estimate this year's tax using Form 1040-ES. A separate cash reserve can help fund the payments; it does not calculate what is due.

Illustrative cash-basis reserve for the first period:

The $5,250 is a reserve, not a verified April payment. Calculate the payment with the tax worksheet. This example reserves against profit after deductible expenses: 30% of gross receipts would instead set aside $12,600.

The 30% is a placeholder, not a rule. Your real percentage depends on filing status, a spouse's income and withholding, your deductions, and whether your state taxes the profit too. Run the Estimated Tax Worksheet in the Form 1040-ES package once, or have a CPA run it, and use a number that is actually yours. Then keep the reserve in a separate account.

When the year is lopsided

Seasonal trades do not earn in four equal pieces. A landscaper bills most of the year between May and September, so a flat quarter of an annual estimate in April is money that has not come in yet.

There is a method for this. The annualized income installment method — Schedule AI of Form 2210 — uses cumulative income and deductions through March, May, August and December to calculate each installment, so a thin winter installment is not automatically an underpayment. It takes bookkeeping for those specific periods, and is worth having prepared for you the first time.

There is also a lever people miss. If you or a spouse has W-2 wages anywhere, tax withheld from those wages is by default treated as paid in equal parts across the year, whenever it was actually taken — see the withholding chapter of Publication 505. Raising that withholding in the autumn can therefore cover a shortfall from earlier in the year in a way a December estimated payment cannot.

If you miss one, pay it late anyway

The estimated-tax underpayment penalty is calculated using the amount and duration of the shortfall and an interest rate. It runs on the shortfall from the day the installment was due until the day you pay it or the April filing deadline, whichever comes first, at a rate the IRS resets each quarter.

Because it adds up by the day, paying the moment you notice costs less than waiting for April. And do not skip the next one because the last one slipped.

If the total is genuinely unaffordable, file the return on time anyway and look at an IRS payment plan. The failure-to-file penalty runs at a much higher monthly rate than the failure-to-pay penalty, so not filing is a far more expensive problem than not paying.

Your state runs a separate calendar

Most states with an income tax run their own estimated-tax system, often on similar dates but with their own forms, thresholds and safe-harbor rules. A handful of states have no individual income tax at all. Check your state revenue department directly rather than assuming the federal dates carry over.

Where the revenue number comes from

Use income and expense records reconciled to your bank and payment records. Under the IRS cash method, income generally belongs to the year received; under accrual accounting, it generally belongs to the year earned. An approved quote establishes neither receipt nor completed work. Keep it as supporting scope paperwork, and use your bookkeeping records and the applicable IRS worksheet to calculate estimated payments.