How to Address a Letter to the IRS: Format, Payment, and Proof

To address a letter to the IRS, use the specific mailing address the IRS assigns to the form or notice you’re sending, based on your state of residence and whether you’re enclosing a payment. There is no single IRS address. A Form 1040 goes to one place, an amended return to another, and a response to a CP2000 notice to a third. Sending your envelope to the wrong processing center can delay it by weeks or cause the IRS to treat a timely filing as late.

Find the Right Address Before You Seal the Envelope

Start with the instructions that came with the form you’re filing. Every IRS form has a “Where to File” chart that matches your state to a mailing address. Because addresses occasionally change after printed instructions have gone out, cross-check against the IRS online directory, which is organized by form number and reflects the current addresses.¹

If you’re replying to an IRS notice, ignore the form instructions. Use the address printed on the notice itself. The IRS routes notice responses to specific units, and sending your reply to a general processing center is one of the most common mistakes people make.

USPS Addresses Are Not the Same as Private Carrier Addresses

The IRS publishes two sets of addresses for most filings: a P.O. Box for items sent through the U.S. Postal Service, and a physical street address for items sent through an approved private carrier like FedEx, UPS, or DHL. Private carriers cannot deliver to P.O. Boxes, so if you ship that way you need the street address for the correct Submission Processing Center.²

One useful simplification: with a private delivery service, the address is the same whether or not you’re enclosing a payment. With USPS, the payment and no-payment addresses often differ.²

Form 1040 Addresses by Region

For individual returns (Form 1040 and 1040-SR), the current groupings look like this:

Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas. Without a payment: Department of the Treasury, Internal Revenue Service, Austin, TX 73301-0002. With a payment: Internal Revenue Service, P.O. Box 1214, Charlotte, NC 28201-1214.
Connecticut, Delaware, D.C., Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Minnesota, Missouri, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, Wisconsin. Without a payment: Department of the Treasury, Internal Revenue Service, Kansas City, MO 64999-0002. With a payment: Internal Revenue Service, P.O. Box 931000, Louisville, KY 40293-1000.
Alaska, California, Colorado, Hawaii, Idaho, Kansas, Michigan, Montana, Nebraska, Nevada, Ohio, Oregon, North Dakota, South Dakota, Utah, Washington, Wyoming. Without a payment: Department of the Treasury, Internal Revenue Service, Ogden, UT 84201-0002. With a payment: Internal Revenue Service, P.O. Box 931000, Louisville, KY 40293-1000.
Arizona, Arkansas, New Mexico, Oklahoma. Without a payment: Austin, TX 73301-0002. With a payment: P.O. Box 931000, Louisville, KY 40293-1000.

These apply to Form 1040 only. Other forms use different addresses, and they can change year to year. Always confirm before mailing.³

What to Put Inside the Envelope

Every piece of correspondence should let the IRS identify you and connect the letter to the right account. Missing identifiers are how payments end up unapplied and responses end up separated from case files.

Full legal name exactly as it appears on your return. If you filed jointly, include both names.
Current mailing address, matching your most recent return unless you’ve filed a change of address.
Social Security Number or Taxpayer Identification Number. This is the single most important identifier the IRS uses to route your documents.
Tax year or years the correspondence relates to.
Form or notice number. If you’re responding to a notice, reference it by number, such as CP2000 or Letter 525.
Signature and date. Tax returns, extension requests, and responses to IRS notices require a handwritten signature to be valid.

When you enclose supporting documents like W-2s, receipts, or bank statements, send copies only. The IRS generally does not return originals, and replacements can be difficult or impossible to obtain.⁴

How to Format the Envelope

Standard envelope formatting applies, but sloppy addressing costs more here than with ordinary mail. A misread digit in a P.O. Box can route your return to the wrong processing center.

Put your full name and return address in the upper left. Center the IRS address on the front, including the full P.O. Box or street address. Print the address rather than writing it in cursive. If you must handwrite, use block letters.

Check that your postage covers the weight. A return with schedules, W-2s, and supporting documents can easily exceed one ounce. An under-stamped envelope gets returned, which can push you past a filing deadline. If in doubt, have the post office weigh it at the counter.

If You’re Mailing a Payment

Make the check or money order payable to “U.S. Treasury.” Do not use “IRS” or “Internal Revenue Service.” On the memo line, write your Social Security Number (or EIN for a business), the tax year the payment covers, and the related form number, such as “2025 Form 1040.”⁵

With an individual return, include Form 1040-V, the payment voucher. The IRS is specific about one point: do not staple or paper-clip the check, voucher, or return together. Place all three loose in the envelope.⁶ Staples jam processing equipment and can damage your check, delaying when the payment posts.

Enclosing a payment usually changes the mailing address. Use the “with payment” column on the “Where to File” chart, not the “without payment” column.

Mailing From Outside the United States

If you live in a foreign country, a U.S. possession or territory, or use an APO/FPO military address, you follow a separate set of addresses. For individual returns without a payment:

Department of the Treasury
Internal Revenue Service
Austin, TX 73301-0215
USA

For individual returns with a payment:

Internal Revenue Service
P.O. Box 1303
Charlotte, NC 28201-1303
USA

The same addresses apply if you file Form 2555 or Form 4563, regardless of where you physically live.⁷ International mail moves more slowly and is harder to track, so an approved private delivery service with tracking is often worth the cost. Build in extra lead time near the deadline.

Get Proof That You Mailed It

For anything with a deadline, proof of mailing is the most important thing you carry out of the post office. The IRS follows a “timely mailing is timely filing” rule: an envelope postmarked on or before the due date is treated as filed on time, even if it arrives days later.⁸

A regular postmark can fade, smudge, or fail to print. If the IRS says it never received your return and you used a plain stamp, you have almost no proof. Certified or registered mail solves that.

Certified Mail

Certified mail gives you a stamped receipt showing the date of mailing, and USPS keeps a delivery record for two years. It costs $5.30 on top of regular postage. For another $4.40, a return receipt (the green card) provides signed confirmation of delivery. Under federal law, a certified mail receipt is treated as proof of delivery if the document is later lost.⁸

Keep the receipt and a photocopy of everything you mailed. If the IRS later says your return never arrived, that receipt is your defense against a late-filing penalty.

Registered Mail

Registered mail is the most secure USPS service. The item is tracked from mailing to delivery and transported under lock, separate from other mail. The date of registration counts as the postmark date for timely-filing purposes.⁹ It costs more and takes longer than certified mail, so most taxpayers find certified sufficient. Registered is better for high-value documents that cannot be replaced.

Approved Private Delivery Services

If you prefer FedEx, UPS, or DHL, only specific service levels qualify for the timely-mailing rule. Using a non-qualifying service means the IRS counts the date the document arrives, not the date you shipped it. The approved services are:¹⁰

FedEx: First Overnight, Priority Overnight, Standard Overnight, 2 Day, International Next Flight Out, International Priority, International First, International Economy.
UPS: Next Day Air Early A.M., Next Day Air, Next Day Air Saver, 2nd Day Air, 2nd Day Air A.M., Worldwide Express Plus, Worldwide Express.
DHL Express: Express 9:00, Express 10:30, Express 12:00, Express Worldwide, Express Envelope, Import Express 10:30, Import Express 12:00, Import Express Worldwide.

Ground services, SurePost, SmartPost, and similar economy options do not qualify. With any private carrier, get a receipt showing the date of mailing, and use the physical street address for the correct Submission Processing Center rather than the P.O. Box.²

1
Internal Revenue Service. Where to File Tax Returns – Addresses Listed by Return Type
2
Internal Revenue Service. Submission Processing Center Street Addresses for Private Delivery Service (PDS)
3
Internal Revenue Service. Where to File Addresses for Taxpayers and Tax Professionals Filing Form 1040
4
Internal Revenue Service. 21.3.3 Incoming and Outgoing Correspondence/Letters
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Internal Revenue Service. Pay by Check or Money Order
6
Internal Revenue Service. 2025 Form 1040-V Payment Voucher for Individuals
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Internal Revenue Service. International – Where to File Form 1040 Addresses for Taxpayers and Tax Professionals
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Office of the Law Revision Counsel. 26 USC 7502 – Timely Mailing Treated as Timely Filing and Paying
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Internal Revenue Service. 1.22.2 United States Postal Service (USPS) Classes of Mail, USPS Additional Services and Small Package Carrier (SPC) Services
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Internal Revenue Service. Private Delivery Services (PDS)