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Where to mail your Oklahoma state tax return

Mailing your Oklahoma Form 511 depends on your situation: Return (do not enclose payment) goes to Oklahoma Tax Commission, PO Box 26800, Oklahoma City, OK 73126-0800, while Payment (Form 511-V voucher, mailed separately) goes to Oklahoma Tax Commission, PO Box 26890, Oklahoma City, OK 73126-0890. Pick the address that matches your return below, sign and date the form, and mail it before the deadline.

Return (do not enclose payment)

Oklahoma Tax Commission
PO Box 26800
Oklahoma City, OK  73126-0800

Use this address for a paper Form 511 where return (do not enclose payment).

Verified September 2026oklahoma.gov

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Other mailing addresses

Payment (Form 511-V voucher, mailed separately)

Oklahoma Tax Commission
PO Box 26890
Oklahoma City, OK  73126-0890

Use this address for a paper Form 511 where payment (form 511-v voucher, mailed separately).

Your name
Your return address

Oklahoma Tax CommissionPO Box 26800Oklahoma City, OK 73126-0800

Your letter, printed and mailed for you.

Key facts

  • Oklahoma splits paper Form 511 returns by address: return (do not enclose payment) vs. payment (form 511-v voucher, mailed separately) — mailing to the wrong one can delay processing.
  • Make checks or money orders payable to the "Oklahoma Tax Commission".
  • Oklahoma explicitly asks you NOT to enclose a payment with Form 511 — if you owe, mail the 511-V voucher and payment separately to its own address.
  • A mailed return is generally considered filed on time if it is postmarked by the state filing deadline — sign and date it, since an unsigned return isn't considered filed.
  • PostPal prints your return and hands it to USPS the next business day for $5 — no printer, envelope, or trip to the post office.

How to send your letter

  1. 1

    Pick the address that matches your situation

    Oklahoma uses a different address depending on whether you're enclosing a payment: Return (do not enclose payment); Payment (Form 511-V voucher, mailed separately). Choose the one below that matches your return.

  2. 2

    Assemble and sign your return

    Attach any required schedules and withholding statements to your Form 511. Sign and date it — an unsigned paper return isn't considered filed.

  3. 3

    Address the envelope exactly

    Use Oklahoma Tax Commission at the address for your situation, shown above. Oklahoma explicitly asks you NOT to enclose a payment with Form 511 — if you owe, mail the 511-V voucher and payment separately to its own address.

  4. 4

    Mail it before the deadline

    A USPS postmark by the filing deadline counts as on time. Upload your return to PostPal and we print, envelope, and mail it within one business day for $5, with a dated confirmation emailed to you.

Common questions

Where do I mail my Oklahoma state tax return?

It depends on whether you're enclosing a payment. For "return (do not enclose payment)," mail it to Oklahoma Tax Commission, PO Box 26800, Oklahoma City, OK 73126-0800. For "payment (form 511-v voucher, mailed separately)," mail it to Oklahoma Tax Commission, PO Box 26890, Oklahoma City, OK 73126-0890.

Does it matter which Oklahoma address I use?

Yes. Oklahoma Tax Commission routes paper returns by mail code, so sending a payment return to the no-payment address (or vice versa) can delay processing, even though the state and ZIP still get it to the right building.

What do I make my check payable to?

The "Oklahoma Tax Commission". Write your Social Security number and the tax year on the check or money order.

Is a mailed Oklahoma return considered on time if it's postmarked by the deadline?

Generally yes — most states, including Oklahoma, treat a return as timely filed if it carries a USPS postmark on or before the filing deadline. Keep proof of mailing for your records; PostPal emails you a dated confirmation.

Can PostPal mail my Oklahoma tax return for me?

Yes. Upload your completed, signed Form 511 and PostPal prints it and mails it to Oklahoma Tax Commission, PO Box 26800, Oklahoma City, OK 73126-0800 (or your correct address, based on your situation) the next business day for $5, with a dated Confirmation of Mailing.

Sources

Addresses verified September 2026 against official sources. Always confirm on the official site before time-sensitive filings.

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