For tax year 2025, filed in 2026, Oklahoma state tax brackets run on a three-tier progressive scale with a top rate of 4.5%, down from the prior six-bracket structure that topped out at 4.75%.1Justia. Oklahoma Code 68-2355 – Tax Imposed – Classes of Taxpayers Residents pay Oklahoma tax on all income no matter where it was earned; part-year residents and nonresidents owe tax only on income sourced within the state.
2026 Income Tax Brackets
Oklahoma taxes income progressively, so each slice of your taxable income falls into a different rate. The brackets took effect January 1, 2026, and the dollar thresholds are not indexed for inflation, meaning they stay the same year after year unless the legislature changes them.
Single Filers and Married Filing Separately
- 0% on the first $3,750 of taxable income
- 2.5% on the next $1,150
- 3.5% on the next $2,300
- 4.5% on everything above $7,200
Married Filing Jointly, Surviving Spouses, and Heads of Household
- 0% on the first $7,500 of taxable income
- 2.5% on the next $2,300
- 3.5% on the next $4,600
- 4.5% on everything above $14,400
Because the 0% bracket shelters the first few thousand dollars of taxable income, many lower-income filers end up owing little or no Oklahoma income tax at all.1Justia. Oklahoma Code 68-2355 – Tax Imposed – Classes of Taxpayers
What Counts as Taxable Income
Your Oklahoma return starts with your federal adjusted gross income. From there, you subtract either the standard deduction or itemized deductions, plus a $1,000 personal exemption for each exemption claimed on the return. The result is your Oklahoma taxable income, which is what the brackets above apply to.
Standard Deduction
For 2026, Oklahoma’s standard deduction mirrors the federal amounts:
- Single or married filing separately: $16,100
- Head of household: $24,150
- Married filing jointly: $32,200
If you’re 65 or older or blind, you get an additional standard deduction of $2,050 (single or head of household) or $1,650 (married filing jointly or separately). Qualifying as both 65-plus and blind doubles the additional amount.
Itemizing Instead
If itemizing produces a bigger deduction, Oklahoma caps total itemized deductions at $17,000, but charitable contributions and medical expenses sit outside that cap and can be deducted in full.2Oklahoma Tax Commission. Oklahoma Tax Commission – File Taxes
Social Security and Retirement Income
Social Security benefits are fully exempt. If your federal AGI includes any Social Security income, you subtract the entire amount on your Oklahoma return.3Oklahoma Tax Commission. Income Tax
For other retirement income, Oklahoma allows two separate exclusions of up to $10,000 each per individual. One covers retirement benefits from federal and Oklahoma government plans, including the Oklahoma Public Employees Retirement System, the Teachers’ Retirement System, the Firefighters’ Pension and Retirement System, and Civil Service pensions. The other covers private retirement income such as 401(k) distributions, 457 deferred compensation plans, traditional IRAs, and employee annuities.4Oklahoma Tax Commission. Chapter 50 Income Tax Rules – Section 710:50-15-49 A retiree drawing from both a government pension and a private 401(k) could therefore exclude up to $20,000 in total.
Military retirement pay is fully exempt with no dollar cap.5MyArmyBenefits. Oklahoma Military and Veterans Benefits
Filing Deadline and Extensions
Oklahoma individual income tax returns for tax year 2025 are due April 15, 2026, which matches the federal deadline in most years.6Oklahoma Tax Commission. Oklahoma Tax Commission Announces 2026 Income Tax Filing Season
If you’ve already filed a federal extension and don’t owe additional Oklahoma tax, the state honors your federal extension automatically. Attach a copy to your Oklahoma return when you eventually file. If you do owe additional state tax, or if you didn’t file federally, submit Form 504-I by April 15 and pay at least 90% of your total state liability by that date.7Oklahoma Tax Commission. Application for Extension of Time to File an Oklahoma Income Tax Return for Individuals
An extension buys time to file, not time to pay. Interest starts accruing on any unpaid balance after April 15 even with a valid extension in place.
How to File and Pay
Residents file on Form 511. Nonresidents and part-year residents use Form 511-NR. Both are available from the Oklahoma Tax Commission website along with instruction packets.8Oklahoma Tax Commission. Forms Your return begins with federal AGI, then applies Oklahoma deductions, exemptions, and adjustments. Make sure names and Social Security numbers match your federal return exactly; mismatches are a common cause of processing delays.
Filing Online
The Oklahoma Taxpayer Access Point (OkTAP) is the state’s portal for filing, paying, and checking refund status.9Oklahoma Tax Commission. Help Center OkTAP You can pay directly from a bank account at no additional cost. Credit and debit card payments go through a third-party processor that may charge up to 4% of the payment amount under the governing statute.10Justia. Oklahoma Code 68-218 – Remittance of Taxes and Fees – Dishonored Checks – ATMs in Commission Facilities
Filing by Mail
Paper returns go to PO Box 26800, Oklahoma City, OK 73126-0800.11Oklahoma Tax Commission. Mailing Addresses for Reporting and Remittances Write your Social Security number on any check or money order. If you’re sending a payment separately with the Form 511-V voucher, mail it to PO Box 26890, Oklahoma City, OK 73126-0890.
Penalties for Late Filing and Payment
Missing the deadline triggers a 5% penalty on the total tax due.12New York Codes, Rules and Regulations. Oklahoma Code 68-2375 – Payment of Tax – Delinquency – Penalties and Interest Interest then accrues at 1.25% per month from the delinquency date until the balance is paid.13Justia. Oklahoma Code 68-217 – Interest and Penalties on Delinquent Taxes – Interest on Refunds On a $2,000 balance, that’s $25 after one month and roughly $300 after a year, on top of the $100 initial penalty.
The OTC will waive the 5% penalty if you pay the full tax and interest within 60 days of receiving a proposed assessment, or if you voluntarily pay when filing an amended return.12New York Codes, Rules and Regulations. Oklahoma Code 68-2375 – Payment of Tax – Delinquency – Penalties and Interest If you expect to owe but can’t file on time, submitting Form 504-I and paying 90% of your estimated liability by April 15 keeps the penalty off entirely. Interest still runs on whatever remains unpaid, but that is far cheaper than the penalty plus interest combination that follows a straight late filing.