Introduction
Form 1040-ES helps individuals estimate and pay U.S. federal income tax during the year when withholding doesn't cover the bill. Freelancers, investors, landlords and business owners hit this most often. Miss it, and you can face an underpayment penalty even if you pay everything at filing time.
For Australia-based readers, scope matters. Form 1040-ES covers U.S. federal estimated tax only. It is separate from Australian PAYG instalments, from any state tax, and from the annual U.S. return. Figures below are for tax year 2026, and all dollar amounts are U.S. dollars.
Key Takeaways
- Form 1040-ES calculates current-year estimated tax and supplies vouchers for mailed payments.
- You generally owe estimates if you expect to owe at least $1,000 after withholding and credits.
- Most people can pay online and skip the voucher, but should keep the worksheet and confirmations.
- Foreign tax credits, treaties, entities and missed instalments often justify professional review.
What Is Form 1040-ES and Who Needs It?
Form 1040-ES, "Estimated Tax for Individuals," is the IRS's pay-as-you-go tool for income that has no tax withheld. Its worksheet projects income tax, self-employment tax and other federal taxes before you file your annual return.
Who may need estimated tax payments?
Common triggers, when nothing is withheld:
- Self-employment and freelance income
- Interest and dividends
- Rent
- Gains from asset sales
- Prizes and awards
- Pension or other income with insufficient withholding
Employees can owe estimates too, if payroll withholding and refundable credits fall short.
How to determine whether you have an obligation
For 2026, IRS Form 1040-ES sets two conditions. Both must apply:
- You expect to owe at least $1,000 after withholding and refundable credits.
- Your withholding and credits will be less than the smaller of 90% of your 2026 tax or 100% of your 2025 tax.
The prior-year return must cover a full 12 months. If your 2025 AGI exceeded $150,000 ($75,000 for married filing separately), the prior-year figure becomes 110%.
Farmers and fishers with two-thirds of gross income from those activities use 66 2/3% for the current-year test, and the 110% rule does not apply.
Look at withholding, credits, filing status, deductions and all income sources together. A rough percentage of business income won't do.
Special considerations for Australia-based taxpayers
First establish why U.S. federal tax applies to you. Typical reasons are U.S. citizenship, resident-alien status, U.S.-source income or a U.S. trade or business.
- U.S. citizens and resident aliens in Australia have the same estimated-tax rules as people in the U.S. The first instalment is due April 15. The automatic two-month filing extension for overseas taxpayers does not move that date.
- Nonresident aliens use the separate Form 1040-ES (NR), not 1040-ES.
- Foreign tax credit: Australian tax paid may offset U.S. tax via Form 1116, and the U.S.-Australia treaty provides double-tax relief, subject to its limits.
- Business structure: Check entity classification before assuming 1040-ES is the right form.
Who may not need to make estimated payments
You owe no 2026 estimates if you were a U.S. citizen or resident alien for all of 2025 and had no 2025 tax liability (total tax of zero, or no filing requirement). Withholding or credits that already cover the required amount also remove the need.
An exception to estimates doesn't remove the duty to file a U.S. return or report the income.
How to Calculate Estimated Tax with Form 1040-ES
Before you start, gather:
- Latest Form 1040-ES package
- Prior-year return
- Current income records and withholding details
- Expected deductions, credits and self-employment figures
Understanding the Estimated Tax Worksheet
The 2026 worksheet runs like this:
- Estimate 2026 AGI.
- Subtract deductions, the qualified business income (QBI) deduction and the Schedule 1-A additional deduction.
- Apply the 2026 tax-rate schedules and add AMT or other taxes.
- Subtract credits, then add self-employment tax.
- Compare 90% of current-year tax with the prior-year amount.
- Subtract withholding, apply the $1,000 test, and set the instalment.
Standard deductions for 2026 are $16,100 (single or married filing separately), $24,150 (head of household) and $32,200 (married filing jointly). Always use the current form's line references, since they change.
Choosing a calculation method
Prior-year tax is a stable planning baseline. Estimating current-year income gives a more accurate figure when your year differs sharply from the last.
Consider the annualized-income method for uneven income: seasonal revenue, a late-year capital gain, a new rental or a big change in deductions. Publication 505 explains it, and Form 2210 Schedule AI applies it. If you use it for one due date, use it for all.
Estimating self-employment and other taxes
Self-employed taxpayers include both income tax and self-employment tax. The rate is 12.4% Social Security plus 2.9% Medicare, applied to 92.35% of net earnings, with a $400 filing threshold. The 2026 draft Schedule SE instructions show a $184,500 Social Security wage base.
The QBI deduction can reach 20% of qualified business income, subject to limits. Capital gains and foreign tax credits can also move the estimate materially.
Recalculating during the year
Revise later instalments when income, expenses, withholding or filing status changes. Keep a note of the assumptions behind each estimate.
Hypothetical example, not official guidance: a consultant estimates $6,000 of tax per instalment, then lands a large contract after the second payment.
Rather than keep paying $6,000, she reruns the worksheet with year-to-date income, subtracts what she has already paid, and divides the remaining tax across the remaining instalments. If income falls, she does the reverse.
Avoiding calculation errors
Reconcile bookkeeping, bank records, Forms 1099, withholding statements, prior-year tax, foreign income details and payments made so far before finalising each estimate. For complex cross-border or business cases, consult Publication 505, the Form 2210 instructions and a qualified professional.
When Estimated Payments Are Due and How to Pay
Current-year payment schedule
| Instalment | Calendar-year 2026 due date |
|---|---|
| 1 | April 15, 2026 |
| 2 | June 15, 2026 |
| 3 | September 15, 2026 |
| 4 | January 15, 2027 |
A date falling on a weekend or legal holiday moves to the next business day. You can skip the fourth instalment if you file the 2026 return by February 1, 2027 and pay the full balance with it.
Fiscal-year taxpayers pay on the 15th day of the 4th, 6th and 9th months, and the first month after year-end. Disaster relief can postpone deadlines for eligible taxpayers, so check IRS notices.
Planning the instalments
You can structure payments in several ways:
- Four equal instalments
- The whole estimate paid early
- Several payments before a single deadline
Timeliness is judged by when each payment arrives. Equal payments suit steady income. Seasonal earners are usually better served by the annualized method.
Electronic payment methods
| Method | Key details |
|---|---|
| IRS Online Account | Pay from a bank account, same day or scheduled up to 365 days ahead |
| Direct Pay | Free; needs a U.S. ABA routing number, no SWIFT codes |
| EFTPS | Free; schedule up to 365 days ahead |
| Card or digital wallet | Processor fees apply, such as 1.75% to 2.95% on credit cards, with $2.50 minimums |
| Foreign-bank wire | For people without a U.S. bank account; the bank may charge a fee |
For wires, complete the IRS Same-Day Taxpayer Payment Worksheet and use tax-type code 10406 for Form 1040 estimated tax. Australia-based payers without a U.S. account will most likely use the wire or a card.
Paying by mail with a 1040-ES voucher
Use the voucher for the right due date, enter your name, address and taxpayer ID, and pay by check or money order. Foreign-address payers mail to Internal Revenue Service, P.O. Box 1303, Charlotte, NC 28201-1303.
Confirm this against the current form, because IRS addresses have been corrected before. Keep the worksheet with your records; don't mail it.
Proving payment and handling special situations
- Save confirmation numbers, bank statements, cancelled checks and mailing proof.
- Keep a ledger showing tax year and instalment for each payment.
- If a payment is misapplied, compare IRS notices (CP23, CP60) with your records and send proof of payment as the notice directs.
How Form 1040-ES Relates to Forms 1040 and 1040-V
Form 1040 versus Form 1040-ES
Form 1040 is the annual return. Form 1040-ES is for estimating and paying during the year. It does not replace the return; you reconcile those estimates on Form 1040.
The 1040-ES payment voucher and worksheet
The worksheet supports your estimate and stays with you. The voucher identifies a mailed payment for a particular period. Online payers need no voucher, but should keep the worksheet and payment confirmations.
Form 1040-V and reporting estimated payments
Form 1040-V accompanies a check or money order for a balance due on your annual return. It isn't an estimated-tax voucher, and you skip it when paying online.
The 2025 Form 1040 reports 2025 estimated payments, plus any 2024 overpayment applied forward, on line 26. Withholding is reported separately.
How to Avoid Underpayment Problems
Understanding penalties
The penalty depends on the amount unpaid, each instalment's due date and how long the shortfall lasts. Paying the balance with your return doesn't erase an earlier-period shortfall. IRS interest on individual underpayments is 7% for the fourth quarter of 2026, and it is set quarterly. The IRS generally calculates the penalty and bills you; Form 2210 applies in specific cases.
Safe-harbour planning
Meeting either safe harbour (90% of current-year tax, or 100%/110% of prior-year tax) avoids the penalty. Waivers are possible for retirement after age 62 or disability, or for casualty, disaster or unusual circumstances, when the penalty would be inequitable. Check the Form 2210 instructions for the year concerned.
Practical compliance checklist
- Estimate income for the year.
- Review withholding and credits.
- Calculate tax on the worksheet.
- Schedule each instalment.
- Confirm and file every payment record.
- Update after material changes.
- Reconcile payments on the annual return.
When professional assistance is useful
Seek help if your situation involves:
- U.S.-Australia cross-border income
- Foreign tax credits or treaty questions
- Entity-level, investment or rental income
- Fluctuating earnings or missed payments
Enrolled agents, CPAs and attorneys can represent you before the IRS using Form 2848.
VJM Global supports Australia-based owners and businesses with U.S. tax compliance and accounting advisory, including Form 1040 preparation.
Bottom line
Form 1040-ES is a planning and payment tool. Accurate estimates, timely payments, tidy records and current IRS guidance keep surprise balances and penalties away.
Frequently Asked Questions
What is Form 1040-ES and what is it for?
It helps individuals calculate current-year U.S. federal estimated tax. It also provides vouchers for payments made by mail.
How can I pay Form 1040-ES estimated taxes?
Pay online through an IRS Online Account, Direct Pay, EFTPS, a card processor or a foreign-bank wire. Alternatively, mail a cheque or money order with the right voucher.
What is a 1040-ES payment voucher and how do I use it?
The voucher identifies a mailed estimated-tax instalment for one due date. Complete it, send it with your cheque or money order to the IRS address in the instructions, and keep the worksheet for your records.
How does Form 1040 differ from Form 1040-ES?
Form 1040 is the annual income tax return. Form 1040-ES supports estimated payments during the year.
Where do I report estimated tax payments on Form 1040?
On the 2025 Form 1040, report them on line 26 with any prior-year overpayment applied forward. Check the current form's instructions, since line numbers can change.
What is Form 1040-V and when do I need it?
Form 1040-V is a payment voucher for a balance due on your annual return, sent with a cheque or money order. It isn't used for estimated instalments or online payments.
