How to Complete and Submit Oklahoma Form 538-S: Sales Tax Relief Credit

Oklahoma Form 538-S is the Tax Commission’s claim form for the Sales Tax Relief Credit, a flat $40 refund per household member that offsets sales tax paid on groceries and other necessities. If you file an Oklahoma income tax return, attach the completed 538-S to your Form 511. If your income is low enough that you don’t owe state income tax, mail the 538-S on its own by June 30 following the tax year.

Who Qualifies

Three things control eligibility: full-year Oklahoma residency, gross household income under a set cap, and no disqualifying circumstances. You must have lived in Oklahoma every day of the tax year.¹

The income cap depends on your household:

$20,000 or less if you (and your spouse, if filing jointly) claim no exemptions beyond yourselves.
$50,000 or less if you claim at least one dependent, if you or your spouse are 65 or older by December 31 of the tax year, or if you or your spouse have a physical disability that substantially limits employment.²

Watch the income figure carefully. Gross household income is broader than the adjusted gross income on your federal return. It includes everything received by every person living in your home, taxable or not: public assistance, child support, workers’ compensation, school grants, veterans’ disability compensation, loss-of-time insurance, military housing assistance, and Roth IRA distributions all count. The one thing you leave out is income deferred for federal tax purposes, like traditional 401(k) or IRA contributions, which get counted later when withdrawn.¹

Two groups can’t claim it. Anyone convicted of a felony who spent any part of the tax year in the custody of the Oklahoma Department of Corrections is ineligible for that year.² And a dependent already claimed on someone else’s Oklahoma return can’t file a separate 538-S.

How to Fill Out the Form

The form runs two pages. Download the current version from the Oklahoma Tax Commission website or pick one up at any OTC office.

Page One: Personal Information and Exemptions

Part 1 collects your name, Social Security number, mailing address, and Oklahoma physical address if it differs. Filing jointly? Add your spouse’s name and SSN on the same lines. Check the disability box if it applies to you or your spouse, and check the separate box if either of you was 65 or older by December 31. If either person died during the tax year or the following year, enter the date of death in the space provided.

Then fill in the exemption boxes at the top:

Box A: 1 for yourself.
Box B: 1 for your spouse if filing jointly.
Box C: the number of qualifying dependents.
Box D: total of A through C. This is your qualified exemption count.¹

Part 2 lists each dependent by full name, age, Social Security number, relationship, and yearly income. Every person needs a complete SSN; missing numbers get the form kicked back.

Page Two: Income and Credit

Part 3 walks through gross household income line by line: wages and salaries (including nontaxable W-2 amounts), interest and dividends, dependents’ combined income from Part 2, Social Security, Railroad Retirement, other pensions and IRA distributions, alimony, and unemployment. Add them up. That total decides whether you’re inside the $20,000 or $50,000 cap.¹

The credit itself is simple math: Box D multiplied by $40. A single filer gets $40. A couple with two dependents gets $160.² If you’re filing Form 511, carry that amount to Form 511, line 25.¹

Documenting a Physical Disability

If you’re using the $50,000 cap on the basis of a physical disability, attach proof to the form. The Tax Commission accepts certification from a state government agency, a physician’s statement, an insurance company certification, proof of eligibility for Social Security disability benefits, or a U.S. Department of Veterans Affairs certification of a service-connected disability.¹ Submit the documentation every year. The Tax Commission doesn’t carry it forward from a prior filing.

Deadlines and Where to Send It

Your deadline depends on whether you file an Oklahoma income tax return.

Filing Form 511: attach Form 538-S and submit by April 15 of the following year. Electronically filed returns get until April 20.
No income tax filing requirement: mail Form 538-S alone by June 30 for the preceding calendar year.³

If you’ve received an extension on your income tax return, the 538-S deadline moves with it. Include a copy of the extension with the form. When the due date falls on a weekend or state holiday, you have until the next business day.¹ Active-duty military stationed outside Oklahoma have until the fifteenth day of the third month after returning to Oklahoma or being discharged from a hospital.⁴

If you file Form 511, attach the signed 538-S to your return. Leaving it off holds up the entire refund; the Form 511 instructions are explicit about that.⁵ You can e-file through the OkTAP portal at oktap.tax.ok.gov or through commercial tax software that supports Oklahoma returns.

Filing 538-S as a standalone claim? Mail it to:

Oklahoma Tax Commission
PO Box 26800
Oklahoma City, OK 73126-0800⁵

How Long the Refund Takes

Processing time depends on how you file and how you get paid:

E-filed with direct deposit: about five to six weeks.
E-filed with paper check: about six weeks.
Mailed return with direct deposit: about ten to twelve weeks.
Mailed return with paper check: about eleven to thirteen weeks.⁶

You can check status through OkTAP or by calling the Oklahoma Tax Commission at 405-521-3160.⁵

Claiming the Credit for a Past Year

Miss a year? You can still file. Oklahoma allows refund claims within three years from the due date of the return or two years from the date the tax was paid, whichever is later. If no return was filed, the claim must come within two years of payment.⁷ Three years back is the practical outer limit for most filers.

Mistakes That Delay Your Refund

The credit is small, but small errors can hold the refund for months or get the claim denied. The ones that trip people up most often:

Missing Social Security numbers. Every person listed needs a complete SSN.
Using federal adjusted gross income in place of gross household income. Oklahoma’s figure is broader, and understating it can trigger a correction or denial.
Claiming the credit on Form 511, line 25, without attaching the actual 538-S pages. The Tax Commission holds the entire refund until they arrive.
Listing a dependent already claimed on someone else’s Oklahoma return. Each exemption can only be used once across all state filings.
Checking the disability box without attached proof. Without documentation, you don’t get the $50,000 cap, and if your income tops $20,000 the claim is denied.

Keep copies of the completed form and every supporting document for at least three years in case the Tax Commission questions the claim later.

1
Oklahoma Tax Commission. Oklahoma Claim for Credit/Refund of Sales Tax – Form 538-S
2
New York Codes, Rules and Regulations. Oklahoma Statutes Title 68 Section 5011 – Eligibility for Relief, Computation, Convicted Felons
3
Oklahoma Administrative Code. Oklahoma Administrative Code 710:50-15-96 – Sales Tax Relief Credit
4
Oklahoma Tax Commission. Help Center: Exemptions
5
Oklahoma Tax Commission. 2025 Oklahoma Resident Individual Income Tax Forms and Instructions
6
Oklahoma Tax Commission. Where’s My Refund Infographic
7
Justia. Oklahoma Statutes Title 68 Section 2373 – Claim for Refund, Return Required, Limitation Period