Tips for filing an Oklahoma state tax return

Wind turbines rise above rolling green fields in Oklahoma, making power from the states notorious weather patterns. Image:

In a Nutshell

Oklahoma has easy-to-understand personal income tax rates that range from .5% to 5%. However, income adjustments and additions, subtractions, deductions and credits can make calculating your Oklahoma state tax a bit confusing. Here’s information that can help.

Editorial Note: Credit Karma receives compensation from third-party advertisers, but that doesn’t affect our editors' opinions. Our marketing partners don’t review, approve or endorse our editorial content. It’s accurate to the best of our knowledge when it’s posted.
Advertiser Disclosure

We think it's important for you to understand how we make money. It's pretty simple, actually. The offers for financial products you see on our platform come from companies who pay us. The money we make helps us give you access to free credit scores and reports and helps us create our other great tools and educational materials.

Compensation may factor into how and where products appear on our platform (and in what order). But since we generally make money when you find an offer you like and get, we try to show you offers we think are a good match for you. That's why we provide features like your Approval Odds and savings estimates.

Of course, the offers on our platform don't represent all financial products out there, but our goal is to show you as many great options as we can.

Oklahoma was the 46th state to join the union. But one of the last states also boasts many American firsts.

The Sooner State is the birthplace of the aerosol can, the parking meter and the shopping cart. It also offers a slew of tax breaks to its residents and a progressive tax code. Here’s what you need to know about filing your personal income tax in Oklahoma.


The basics of Oklahoma state tax

For the most part, Oklahoma’s tax return has a lot in common with your federal return. But there are some key differences to know before you start filling out your return.

Taxing body

The Oklahoma Tax Commission regulates income tax in the state. If you have questions about your Oklahoma state tax, you can call the taxpayer service center at 1-405-521-3160. Alternatively, if you live in the Oklahoma City or Tulsa metro areas, you can visit one of the commission’s offices.

Filing and payment deadline

Oklahoma state income tax returns are typically due on the same day as federal returns — April 15. There are, however, a few exceptions to this rule.

  • If you file your return and pay any tax you owe electronically, you have until April 20 to file and pay what you owe. If you don’t pay electronically on time, you’ll face interest and penalties.
  • If the IRS allows you a later filing due date for your federal return, you can file your Oklahoma state tax return by that later date as well. You’ll need to write your disaster designation at the top of your return.
  • If Tax Day falls on a weekend or holiday, the due date is the next business day.

If you can’t file on time, you can apply for a six-month extension. If you owe money, you’ll still need to pay at least 90% of what you owe by the original due date to avoid a penalty.

Filing statuses

You’ll typically use the same filing status for your Oklahoma state tax return as you do for your federal tax return. These include …

  • Single
  • Head of household
  • Married filing jointly
  • Married filing separately
  • Qualifying widow(er) with a dependent child

The one exception to this rule is if a married couple files a joint federal return but one spouse is a full-year Oklahoma resident and the other is a full-year nonresident civilian (non-military). In this case, they would need to file as married filing separately on their Oklahoma return or file jointly and report all income from both spouses to be taxed at the Oklahoma rate.

How does filing status affect your federal tax bill?

Oklahoma income tax rates

Oklahoma has a progressive personal income tax, with rates of 0.5%, 1%, 2%, 3%, 4% and 5%. Your marginal tax rate will depend on your filing status and taxable income. Most brackets also pay a set dollar amount of tax.

Oklahoma state tax deductions and credits

Oklahomans can either take a standard deduction for their state taxes or itemize deductions. Your choice must match whatever you did on your federal return.

For example, if you took the standard deduction on your federal return, you must take the Oklahoma standard deduction for your filing status on your state return. If you claim itemized deductions on your federal tax return, you’ll have to claim them on your state return too — even if your total itemized deductions are less than the state’s standard deduction.

Standard deductions

For 2018, the Oklahoma state standard deductions are …

  • Single: $6,350
  • Married filing jointly: $12,700
  • Married filing separately: $6,350
  • Head of household: $9,350
  • Qualifying widow(er) with a dependent child: $12,700

In 2017, before Congress passed the Tax Cuts and Jobs Act, the Oklahoma Legislature passed a law that basically froze the state’s standard deductions at these levels. Since the new federal standard deductions are significantly higher than the state’s, Oklahoma would have lost a lot of revenue if it had adopted the new federal standard deduction amounts.

Additionally, the Oklahoma law preserved the state’s personal exemptions, which are $1,000 for taxpayers, their spouses and their dependents. People who are blind or 65 or older and who meet income qualifications may also be eligible for an additional $1,000 exemption.

When you do your Oklahoma state income tax return (Form 511), you’ll take your itemized deductions or standard deduction after determining your adjusted gross income. .

Income adjustments

States use income adjustments, such as subtractions and additions, as well as deductions and credits, to help determine the portion of a taxpayer’s income that will be subject to the state’s income tax. In Oklahoma, you report these adjustments on several different schedules. Here are some of the adjustments from 2017.

529 plan contribution deductions

If you’ve contributed to an Oklahoma 529 college savings plan or OklahomaDream 529 account, you may be able to deduct up to $10,000 of the amount contributed (or $20,000 if you’re filing a joint return).

If you contribute more than the deduction limit, you can carry forward excess contributions for up to five years.

A deduction for providing foster care

If you contract with a child-placing agency to provide foster care, you can deduct up to $5,000 in expenses (or $2,500 if you’re married but choose to file separately).

Learn about federal tax breaks for parents

Subtractions for certain types of retirement income

Oklahoma allows residents to take subtractions from taxable income for a variety of types of retirement income, including …

  • Social Security benefits that were included in federal adjusted gross income
  • Federal Civil Service Retirement benefits in lieu of Social Security
  • Oklahoma state or federal civil service retirement benefits
  • Other types of retirement benefits up to $10,000 or the amount included in federal adjusted gross income, whichever is less

You must meet qualifications in order to take these subtractions.

Subtractions for certain types of military pay

You may be able to take a subtraction for some or all of certain kinds of military pay. For example, you can exclude military retirement benefits from taxable income — up to $10,000 or 75% of the benefits you received, whichever is more. Your deduction can’t exceed the amount included in your federal adjusted gross income.

The spouse of a military service member who is killed in a combat zone can also exclude any payment received from the Department of Defense as a result of their spouse’s death in the taxable year in which their military spouse was killed.

Oklahoma state tax credits

The state also offered some tax credits for 2017 which may be available in 2018.

  • If you’ve completed Council on Firefighter Training and have your signed COFT form, you may qualify for a $200 or $400 credit, depending on the level of training.
  • If your federal adjusted gross income is $100,000 or less and you qualify for a credit for childcare expenses or the child tax credit on your federal return, you can also claim a credit on your state return. The amount of the credit is the greater of 20% of your federal credit for childcare expenses or 5% of your federal child tax credit. You’ll need to complete a worksheet to calculate the amount of your credit.
  • If you qualify for the federal earned income credit, you can take the Oklahoma earned income credit on your state return (equal to 5% of your federal credit). You’ll need to complete a worksheet to calculate the amount of your credit.

How to file your Oklahoma state tax return

If you’re a full-year resident and filed an Oklahoma state tax return in the previous tax year, you can typically e-file your return for free using the OkTAP system. You may also be able to file for free through an approved software vendor. Be aware, some vendors may charge a fee if you don’t meet income, age or other requirements. Credit Karma Tax®, an Oklahoma-approved tax filing service, never charges a fee to file your single-state and federal returns.

If you want to file a paper return, you can download your forms from the Oklahoma Tax Commission website. Check the website for mailing addresses based on your return type.

If you owe and can’t pay

If you have a tax bill but can’t pay the full amount by the due date, you may be able to qualify for an installment plan.

Pay what you can when you file your tax return, and the tax commission will send you a bill for the balance, as well as separate bills for any penalties and interest. You can either pay those bills if you’re able or use OkTAP’s “Request a Payment Plan” feature to see if you qualify to set up a payment plan.

If you can’t get a payment plan through OkTAP, you can contact the compliance division of the tax commission to try to make other arrangements.

Keep in mind though, that you’ll be assessed a penalty on the income tax due plus monthly interest each until you’ve paid in full.

Tracking your Oklahoma tax refund

If you’re expecting a tax refund, you can check the status online through the Taxpayer Access Point system or by calling the state’s automated service at 1-405-521-3160.

Either way, you’ll need to provide the last seven digits of your Social Security number or individual taxpayer identification number, the refund amount and your ZIP code.


Bottom line

Oklahoma offers low tax rates for low-income families. Plus, it provides plenty of adjustments to income and tax credits to help filers save at tax time. Make sure to file your Oklahoma state tax return on time and pay what you owe on time and in full to avoid penalties and interest charges. Plus, take the time to check for tax breaks that you qualify for to reduce how much you owe.