Mail Form 8606 by itself to the same IRS service center that would receive your paper Form 1040 filed without a payment. That means one of three addresses in Kansas City, Ogden, or Austin, chosen by your state of residence. If you’re filing Form 8606 with a tax return, it simply goes wherever that return goes.1Internal Revenue Service. Instructions for Form 8606 (2025)
The IRS shifts state assignments periodically, so confirm your address on the IRS “Where to File” page before you seal the envelope.2Internal Revenue Service. Where to File Paper Tax Returns With or Without a Payment
The Three IRS Addresses for a Standalone Form 8606
Kansas City, MO
Department of the Treasury, Internal Revenue Service, Kansas City, MO 64999-0002.
Use this address if you live in Connecticut, Delaware, District of Columbia, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Minnesota, Missouri, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, or Wisconsin.2Internal Revenue Service. Where to File Paper Tax Returns With or Without a Payment
Ogden, UT
Department of the Treasury, Internal Revenue Service, Ogden, UT 84201-0002.
Use this address if you live in Alaska, California, Colorado, Hawaii, Idaho, Iowa, Kansas, Michigan, Montana, Nebraska, Nevada, North Dakota, Ohio, Oregon, South Dakota, Washington, or Wyoming.2Internal Revenue Service. Where to File Paper Tax Returns With or Without a Payment
Austin, TX
Department of the Treasury, Internal Revenue Service, Austin, TX 73301-0002.
Use this address if you live in Alabama, Arizona, Arkansas, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, or Texas.2Internal Revenue Service. Where to File Paper Tax Returns With or Without a Payment
A standalone Form 8606 needs a couple of things that don’t apply when the form is stapled to a return. Fill in your mailing address on page 1, and sign and date page 2. The signature is your attestation under penalty of perjury, and the IRS can reject a form that’s missing it.1Internal Revenue Service. Instructions for Form 8606 (2025)
When Form 8606 Goes With Your Tax Return Instead
Most filers never mail Form 8606 by itself. If you’re filing a Form 1040, 1040-SR, or 1040-NR, attach Form 8606 and send the whole packet to the address that applies to your return. If you e-file, the form transmits electronically through your tax software as part of the return. The IRS Free File Fillable Forms program supports Form 8606 for tax year 2025.3Internal Revenue Service. Free File Fillable Forms: Program Limitations and Available Forms
One wrinkle for married couples: if both spouses have reportable IRA activity, each needs a separate Form 8606, even on a joint return. Enter only the name and Social Security number of the spouse whose activity that copy covers.1Internal Revenue Service. Instructions for Form 8606 (2025)
When Form 8606 Is Due
Form 8606 is due at the same time as your Form 1040, generally April 15, including any extension you’ve been granted. That deadline applies to standalone filings too. If you aren’t required to file a tax return at all, your Form 8606 is still due by the date your return would have been due.1Internal Revenue Service. Instructions for Form 8606 (2025)
Filing late is better than not filing. The IRS can assess a $50 penalty for a missed Form 8606 and a $100 penalty for overstating your basis, but reasonable cause can excuse either one.4Office of the Law Revision Counsel. 26 USC 6693 – Failure to Provide Reports on Certain Tax-Favored Accounts or Annuities The bigger practical risk is losing track of basis. Without a Form 8606 on file, you may have no way to prove which portion of a future IRA withdrawal was already taxed.
How to Prove You Mailed It
The IRS does not send a receipt when it processes a standalone Form 8606. If timely filing ever becomes an issue, you’re the one who has to prove it.
USPS Certified Mail with a return receipt is the standard approach. Under the IRS mailbox rule, the postmark date counts as your filing date, so an envelope postmarked by the deadline is timely even if it arrives after. Private carriers work too, but only specific service tiers from FedEx, UPS, and DHL qualify for the same postmark-date protection. Standard ground shipping does not. The IRS publishes the approved list, and it’s worth checking before you ship, because a non-qualifying tier means the delivery date controls whether the filing was timely.5Internal Revenue Service. Private Delivery Services (PDS)
Keep a photocopy of the signed form with your mailing receipt. The IRS instructions specifically recommend retaining copies of every Form 8606 you file, along with supporting documents, because you may need them to verify the non-taxable portion of distributions decades later.1Internal Revenue Service. Instructions for Form 8606 (2025)
If You Need to Correct a Form 8606 You Already Sent
If you discover an error on a Form 8606 from a prior year, such as a wrong basis amount, a missing conversion, or a contribution that should have been deductible, fix it by filing a corrected Form 8606 along with Form 1040-X. The corrected 8606 shows the revised figures, and the 1040-X explains what changed.1Internal Revenue Service. Instructions for Form 8606 (2025)
The same process lets you switch a nondeductible contribution to a deductible one, or the reverse, within the time limit for Form 1040-X. If you missed the regular deadline but catch the error within six months of the original due date (not counting extensions), you can still file the amendment by writing “Filed pursuant to section 301.9100-2” on the amended return.1Internal Revenue Service. Instructions for Form 8606 (2025)
Basis errors compound. Each year’s Form 8606 builds on the prior year’s numbers, so a mistake in 2022 gets carried forward on every form after it. Correcting the root year and re-filing the years that followed is tedious, but leaving the error in place tends to cost more over time.