On your tax return, use the mailing address where you actually receive mail on the day you file — not the address where you lived during the tax year. That is the short answer to what address to put on a tax return: if you moved in January and file in April, your January address goes on the return, because the IRS will send every future refund check, adjustment, and legal notice to whatever address you write on that form.
The Basic Rule
Form 1040 asks for a street number, street name, and any apartment, suite, or room number, followed by city, state, and ZIP code. Enter the address where a letter mailed the day you file would find you. If you have moved since January 1 of the tax year, use the new one.
An incomplete or outdated address can bounce refund checks and adjustment notices back to the IRS as undeliverable. The agency also matches the address you enter against its records, so consistency helps prevent identity-verification delays.
P.O. Boxes, Private Mailboxes, and In Care Of
You can put a P.O. Box on the street address line, but only if your post office does not deliver mail to your home. If your house or apartment does get regular delivery, use the physical street address instead.
A private mailbox at a commercial mail receiving agency such as a UPS Store has to be formatted a specific way. The USPS requires “PMB” (or “#”) followed by the box number as part of the street address line, so you write something like “123 Main St PMB 456” rather than listing the box number by itself.1Postal Explorer. 602 Addressing
If your mail goes to someone else’s home, put that person’s name on the “in care of” (c/o) line and the street address on the address line. That tells the carrier to deliver an envelope addressed to you at a household where your name is not on the mailbox.
Joint Filers Living Separately
A joint return has room for only one address. If you and your spouse live apart, pick the one where you want the IRS to send refunds and correspondence. That address becomes the last known address for both spouses.
If you later separate or move to different places, each spouse should notify the IRS of their own new address. Once the IRS has been told the two of you live at separate residences, it will send duplicate copies of future notices, including deficiency notices, to each spouse.2Office of the Law Revision Counsel. 26 U.S. Code 6212 – Notice of Deficiency
Foreign Addresses
If you live outside the United States, Form 1040 has separate fields for a foreign address. Put only the city name on the city line. Below it are separate fields for the foreign country, the province or state, and the foreign postal code. Spell out the country name in full without abbreviating it.3Internal Revenue Service. Instructions for Form 1040 (2025)
International mail to and from the IRS takes considerably longer than domestic correspondence. If you expect a paper refund check abroad, allow extra time, or choose direct deposit to skip the mail altogether.
Military APO, FPO, and DPO Addresses
Service members stationed overseas do not use foreign city or country fields. Enter APO (Army/Air Post Office), FPO (Fleet Post Office), or DPO (Diplomatic Post Office) in the city field. In the state field, use the military two-letter code: AA for the Americas, AE for Europe, the Middle East, Africa, and Canada, or AP for the Pacific.4USPS. Military and Diplomatic Maila>
Do not add the actual foreign city or country name anywhere. Military mail routes on the APO/FPO/DPO designation and ZIP code, and including foreign location details can push the mail into a foreign postal network by mistake.
If You Do Not Have a Permanent Address
You still have to list a mailing address. A shelter, a social services organization, a community health clinic, or a trusted friend or relative can all work, provided you have permission and mail sent there will reach you. If a friend or relative agrees, use the in-care-of format so the carrier delivers it properly. What matters is that IRS correspondence can reliably find you at whatever address you write down.
Why the Address You Choose Matters Later
The IRS treats the address on your most recently filed and properly processed return as your “last known address” for every future notice, unless you have given the IRS clear notice of a different one.5eCFR. 26 CFR 301.6212-2 Definition of Last Known Address That includes a Notice of Deficiency, the certified letter the IRS sends when it believes you owe additional tax. You get 90 days to petition the U.S. Tax Court (150 days if you are outside the country), and that deadline cannot be extended.6Taxpayer Advocate Service. 90-Day Notice of Deficiency
If the notice was mailed to your last known address and you never saw it because you moved, it is still legally valid. The clock runs whether the letter reaches you or not. Once it expires, the IRS assesses the tax and starts collecting, and you have lost the right to challenge the amount in Tax Court before paying.2Office of the Law Revision Counsel. 26 U.S. Code 6212 – Notice of Deficiency
How to Update Your Address After Filing
If you move after filing, the address on your last return stays in IRS records until you actively change it. A change of address filed with the U.S. Postal Service is not a reliable substitute; the IRS may eventually pick up a new address through the USPS database, but that is not guaranteed, and not all post offices forward government checks.7Internal Revenue Service – IRS.gov. Address Changes
You have four ways to notify the IRS directly:
- File Form 8822, the dedicated change-of-address form, and mail it to the address listed in the form’s instructions. Processing takes four to six weeks.8Internal Revenue Service. Form 8822, Change of Address
- Put the new address on your next return; filing updates the records automatically.
- Send a signed written statement with your full name, Social Security number or ITIN, and both your old and new addresses to the IRS office where you filed your last return.
- Call 800-829-1040 or visit a local Taxpayer Assistance Center in person. Be ready to verify your identity.7Internal Revenue Service – IRS.gov. Address Changes