Introduction
If you live in Australia and owe U.S. estimated tax, the right mailing address depends on your filing category, the form, and whether you're paying an estimate or settling a return. Get it wrong and your payment can land in the wrong lockbox.
Australia falls under the IRS "foreign country" instructions for Form 1040-ES. The address is below, but lockbox addresses change. The IRS even issued a correction for the 2026 form, so check IRS.gov before every payment.
This guide covers the address, how to prepare and mail a payment from Australia, deadlines, online alternatives, and what to do if you used an old address.
Key Takeaways
- Confirm the current 1040-ES address on IRS.gov before each payment.
- Form 1040-ES, Form 1040-V and state payments each have separate instructions.
- Electronic payment is usually easier from Australia; if you mail, keep full records.
- Keep proof of payment, mailing and the tax year it applies to.
Where Should You Mail Form 1040-ES?
The foreign-country address
For the 2026 Form 1040-ES, payments from a foreign country, Australia included, go to:
Internal Revenue Service P.O. Box 1303 Charlotte, NC 28201-1303 USA
The 2026 Form 1040-ES lists this same address for several other categories:
- American Samoa or Puerto Rico filers (including a section 933 exclusion)
- APO/FPO addresses
- Filers of Form 2555 or Form 4563
- Dual-status aliens
- Nonpermanent residents of Guam or the U.S. Virgin Islands
This does not cover every U.S. possession. Check the row that applies to you.
How domestic addresses differ
Taxpayers whose filing address is in a U.S. state use one of two domestic lockboxes, in Charlotte, NC (P.O. Box 1300) or Louisville, KY (P.O. Box 931100), depending on the state.
If you live in Australia, do not choose a lockbox because your tax preparer or former home is in a particular state. Use the foreign-country address.
Forms printed before February 13, 2026 may carry an incorrect address, per the IRS correction page.
Other forms and other tax authorities
- Form 1040-ES covers current-year estimated instalments. Form 1040-V accompanies a balance due on a Form 1040 return. Don't reuse one form's address for the other.
- State tax payments go to the relevant state tax authority, never inside a federal envelope.
- The IRS doesn't accept 1040-ES instalments through the Australian Taxation Office.
How to Prepare and Mail an Estimated Tax Payment
Complete the voucher
Use the voucher for the installment you're paying and check the printed tax year. Fill in:
- Payment amount
- Your first and last name and SSN (or ITIN)
- Spouse's name and SSN, for a joint payment
- Street address, city, state and ZIP, or foreign country, province and postal code
Details should match your IRS account.
Prepare the cheque or money order
Make it payable to United States Treasury. Never send cash. Write your SSN and "2026 Form 1040-ES" on it. The IRS's check instructions also suggest including your name, address and tax year.
One caution: the form doesn't say a cheque must be drawn on a U.S. bank, but nothing guarantees a foreign-bank cheque will be accepted or clear smoothly. Ask your bank, or pay electronically.
Address and post the envelope
A sensible layout:
- Internal Revenue Service
- P.O. Box 1303
- Charlotte, NC 28201-1303
- USA
Add your return address and enough international postage. Only USPS delivers to P.O. Boxes, so a private courier such as DHL, FedEx or UPS can't be used for this address.
Timeliness matters too. The U.S. timely-mailing rule covers U.S. mail with proper addressing and postage, and 26 CFR 301.7502-1 says it doesn't apply to payments deposited with another country's postal service.
Australia Post registered mail gives you tracking and proof of posting, but not that statutory protection. Mailing early is your best protection.
Keep evidence
Keep:
- A copy of the completed voucher
- A photo of the cheque
- The postal receipt and tracking details
- Bank-clearing evidence once it appears
Mail from Australia takes time to arrive, so these records matter if the payment is questioned.
Who Needs to Pay and When Are Payments Due?
What estimated payments cover
Form 1040-ES covers current-year federal income tax, plus self-employment tax and other amounts withholding doesn't cover. Common triggers include:
- Freelance or business income
- Rental income
- Investment income
- Foreign income
- Large one-off gains
Having these doesn't automatically mean you must pay.
Who must pay
For 2026, payments are generally required if you expect to owe at least $1,000 after withholding and refundable credits, and expect withholding to be less than the smaller of:
- 90% of your 2026 tax, or
- 100% of your 2025 tax (110% if 2025 AGI exceeded $150,000, or $75,000 if married filing separately)
U.S. citizens and resident aliens in Australia remain subject to these rules. The Foreign Earned Income Exclusion and foreign tax credits don't remove the need to calculate. Publication 505 has a worksheet that accounts for tax on excluded income.
Quarterly due dates
| Instalment | 2026 due date |
|---|---|
| First | April 15, 2026 |
| Second | June 15, 2026 |
| Third | September 15, 2026 |
| Fourth | January 15, 2027 |
If a date falls on a weekend or legal holiday, payment is due the next business day. Disaster postponements can apply in affected areas.
The automatic two-month extension for taxpayers abroad covers filing and paying the annual return, not the instalment schedule. You can adjust later instalments if income changes, but allocate each payment to the correct period.
Professional support
Australia-based U.S. taxpayers with business, investment or foreign income often benefit from help calculating estimates. VJM Global's U.S.-compliant tax professionals prepare Form 1040 returns and can support this review. They don't make IRS payments on your behalf, and no result is guaranteed.
Electronic Alternatives, Address Errors, and Final Checks
Mail versus electronic payment
| Option | Key points |
|---|---|
| Direct Pay | Free; schedule up to 365 days ahead; needs a U.S. bank account and routing number |
| EFTPS | Free; existing individual users only, as new individuals can't enrol |
| International wire | Initiated by your foreign bank; must be in U.S. dollars; bank fees may apply |
| Card | Fees apply, for example $2.15 debit via Pay1040 or 1.75% credit (minimum $2.50) |
For Direct Pay, select Form 1040 Income Tax, Estimated Tax, and the tax year. Electronic payment gives confirmation and avoids international postal delays. Confirm card fees on the IRS card page before paying.
If you used an old address
The IRS doesn't promise to forward a misaddressed payment or preserve its original postmark, and the timely-mailing rule requires a proper address. Don't assume protection. Instead:
- Keep proof of mailing
- Monitor your IRS online account and notices
- Contact the IRS or a tax professional if a payment is misapplied or a penalty notice arrives
Penalties are calculated per installment period. Waivers are limited, such as disaster or unusual circumstances, and ordinary reasonable cause alone isn't a general waiver.
Mailing checklist
- Tax year and installment period confirmed
- SSN or ITIN on voucher and cheque
- Voucher and payee ("United States Treasury") correct
- Amount right
- Current IRS address verified
- Postage paid, tracking or receipt kept
IRS addresses, procedures, deadlines and electronic-payment rules can change. Check IRS.gov or the current Form 1040-ES instructions before paying.
Frequently Asked Questions
Where do I mail my federal estimated (Form 1040-ES) tax payments?
From Australia, you generally use the IRS foreign-country address on Form 1040-ES (currently P.O. Box 1303, Charlotte, NC 28201-1303). Verify it on IRS.gov first.
How do I make estimated tax payments?
Calculate your amount using Form 1040-ES, then pay by mail or electronically through Direct Pay, EFTPS (existing users) or wire. Apply each payment to the correct period.
How do I make a payment to the IRS by mail?
Use the correct voucher and a cheque or money order payable to United States Treasury. Address it accurately, add adequate postage, and keep proof of mailing.
When do I need to pay quarterly estimated taxes?
For 2026: April 15, June 15, September 15 and January 15, 2027. Dates shift for weekends, holidays or disaster relief.
What is the best way to send tax payments to the IRS?
Electronic payment offers confirmation and speed. Mail suits those without a U.S. bank account. Weigh speed, fees and recordkeeping.
How do I address my envelope to the IRS?
Copy the current Form 1040-ES recipient address exactly, add a return address and enough postage, and never rely on an older voucher's address.
