Where to Mail Form 3520: IRS Ogden Service Center

The address

Mail Form 3520 to:

Internal Revenue Service Center P.O. Box 409101 Ogden, UT 84409

This is the only place to mail Form 3520. It does not go with your Form 1040. It does not go to your local IRS service center. It does not go to Cincinnati or Austin or Kansas City. Ogden, Utah, P.O. Box 409101.

If you are filing Form 3520-A (the related form for foreign trust owners) instead, the address is the same but with a different P.O. Box — 409101 is for Form 3520; do not use that for 3520-A.

Use certified mail, return receipt

The IRS does not send acceptance letters for Form 3520. You file it and never hear back unless something is wrong. That means your USPS certified-mail receipt is the only proof that you filed on time.

Steps:

1. Take your Form 3520 + the envelope to a USPS counter.
2. Ask for Certified Mail with Return Receipt (PS Form 3811, the green card).
3. The clerk attaches a barcoded certified-mail label and hand-cancels the certified portion.
4. You pay (~$11 total — $4.85 certified + ~$3.65 return receipt + first-class postage).
5. Keep the receipt. The IRS receives the form, signs the green card, and USPS mails it back to you in a week or two.

If you wait until April 15, go to the post-office counter in person and ask the clerk to hand-cancel the certified label in front of you. Mailbox-drop and self-service kiosks can postmark the next business day depending on the time you dropped it.

What the envelope should say

Plain white #10 business envelope is fine. Address it exactly:

Internal Revenue Service Center P.O. Box 409101 Ogden, UT 84409

Your return address goes in the upper-left corner. The certified-mail label goes above the address block.

Do not put "Form 3520" in the address — the P.O. Box already routes to the right team. Do not write "Confidential," "Personal," or "Attn:" anywhere on the envelope.

What goes inside the envelope

• The signed Form 3520 (wet pen signature on page 1, plus on the certification statement at the bottom).
• Any required attachments — if Part I or Part II applies, you may need to attach supporting trust documents. For Part IV (foreign gifts), no attachments are required by the IRS.
• A photocopy of your most recent Form 1040 page 1 if helpful for identity verification (optional, not required).

Do not include payment — Form 3520 generates no tax for most filers. If you do owe estimated tax, that goes on a separate IRS payment, not enclosed.

What about our Concierge kit

If you bought our Concierge tier we ship you a printed Form 3520, a pre-stamped certified-mail envelope already addressed to Ogden, and a return-receipt postcard with your address on it. You sign in pen on the printed form, slide it into the envelope, drop it at any USPS mailbox. The certified-mail label is already on the envelope.

You still keep your USPS-tracking number — we email it to you when we ship the kit and you can use it to confirm the IRS received your filing.

---

3520file is software, not a CPA firm or law firm. We prepare IRS Form 3520 based on the facts you provide. For advice on your specific situation, talk to a tax attorney or CPA. The above is plain-English explanation, not tax advice.