Your Complete Guide on How to File Your Oklahoma Tax Return for 2020

Filing your 2020 Oklahoma tax return is essential for individuals and small business owners. Understanding the process ensures you meet your legal obligations, avoid penalties, and maximize any refund you may be entitled to receive. Whether you are a full-year resident, a part-year resident, or a nonresident with Oklahoma income, knowing the correct steps will help you file accurately and on time.

Oklahoma taxes are based on your income, deductions, and applicable credits for the year. The state requires different forms and procedures depending on your residency status and the type of income you earn, such as wages, business income, or other taxable sources. Because each situation is unique, reviewing the state’s requirements carefully before you begin is essential. This guide will explain the process in clear, practical terms so you can confidently approach filing.

Throughout this article, you will find updated information, deadlines, and form details related to the 2020 tax year. We will cover how to gather the proper documents, choose the correct forms, complete each section of your return, and submit it using the best method. By following these steps, you can verify that your return is complete, reduce the risk of errors, and ensure your filing is reviewed promptly by the Oklahoma Tax Commission.

Overview of Oklahoma State Income Tax for 2020

Oklahoma’s income tax system applies to residents, part-year residents, and nonresidents with income from Oklahoma sources. For the 2020 tax year, you must file an Oklahoma tax return if your gross income exceeds the standard deduction plus personal exemptions for your filing status. These thresholds determine whether you qualify to submit a return and vary based on your situation:

Single filers: $7,350
Married filing jointly: $14,700
Married filing separately: $7,350
Head of household: $10,350
Qualifying widow(er) with dependent child: $13,700

Part-year residents follow the same income limits for the portion of the year they lived in Oklahoma and must also file if they earned at least $1,000 from Oklahoma sources while living elsewhere. Nonresidents are required to file if they received $1,000 or more in wages or other taxable income from Oklahoma.

For 2020, the filing deadlines were April 15, 2021, for paper returns and April 20, 2021, for electronically filed returns, provided payments were made electronically. Several significant changes were updated for the year, including a new credit for qualified software or cybersecurity employees, a higher annual cap for the Railroad Modernization Credit, and a deduction for contributions to a home-buyer savings account. The state also introduced an option to donate to the Oklahoma Silver-Haired Legislature and Alumni Association programs. Understanding these rules and updates is essential in ensuring your return is accurate and complete.

Understanding the Required Forms

The forms you need to file your 2020 Oklahoma tax return depend on your residency status and the type of income you earned. Using the correct form is essential because it ensures your return is processed correctly and helps avoid delays. Oklahoma provides separate forms for residents, part-year residents, and nonresidents, as well as additional schedules and credits for specific situations. For full-year residents, the main document is Form 511—Oklahoma Resident Income Tax Return, which covers income, deductions, and credits. You can download the 2020 Oklahoma Resident Individual Income Tax Forms and Instructions from the Oklahoma Tax Commission’s website to review filing requirements and complete your return accurately.

For Oklahoma residents

Form 511 – Oklahoma Resident Income Tax Return: This is the main form for full-year residents. It covers income, deductions, credits, and tax calculations. You can download the form directly from the Oklahoma Tax Commission’s website.

For part-year residents and nonresidents

Form 511NR – Oklahoma Nonresident and Part-Year Resident Income Tax Return: This form allows you to allocate income between Oklahoma sources and all sources, ensuring you pay state taxes only on Oklahoma-related income.

For electronic filing

Form 511EF – Oklahoma Individual Income Tax Declaration for Electronic Filing: Required in certain e-file situations to verify information provided during the filing process.

Common schedules and credits

Schedule 511-A: Adjustments to income.
Schedule 511-B: Oklahoma-specific additions and subtractions.
Schedule 511-C: Deductions and exemptions.
Schedule 511-D: Itemized deductions.
Form 538-S: Sales Tax Relief Credit.
Form 511CR: Other credits, such as small business or investment incentives.
Form 511TX: Credit for taxes paid to another state.
Form OW-8-ES: Estimated tax payment voucher.
Form 504-I: Application for an extension of time to file.

For small business filers
Sole proprietors must include a copy of their Federal Schedule C (Profit or Loss from Business) and any corporate or business-related credits claimed on Form 511CR. Accurate business records will help you verify your eligibility for deductions and credits.

Step-by-Step Instructions to Complete Your Return

Filing your 2020 Oklahoma tax return is easier when you follow a transparent, organized process. Completing your federal return first is essential, as many figures transfer directly to your state forms. Suppose you are a part-year resident or nonresident. In that case, you will need Form 511NR—Oklahoma Nonresident and Part-Year Resident Income Tax Return to allocate income between Oklahoma and other states. Hence, you only pay tax on Oklahoma-related income. Before you begin, you can download the 2020 Form 511NR and instructions here from the Oklahoma Tax Commission’s website.

1. Gather Your Documents

Before you start, collect all the paperwork and records you need:

W-2 forms from employers showing your wages and Oklahoma taxes withheld.
1099 forms for other taxable income, such as interest, dividends, or contract work.
Documentation for deductions, credits, and business expenses.
A copy of your prior year Oklahoma tax return for reference.
Bank account details if you want your refund by direct deposit.

2. Complete Your Federal Tax Return

Your Oklahoma return relies on information from your federal return, including adjusted gross income and certain deductions. File your federal return first to transfer the correct numbers without guesswork.

3. Enter Your Personal Information

Fill in your name, address, Social Security Number, and filing status. Make sure this matches your federal return. Include all exemptions you qualify for, such as dependent or blind exemptions.

4. Report Your Income

Start with your Federal Adjusted Gross Income (AGI) from your federal return.
Add Oklahoma-specific income adjustments on Schedule 511-A.
Subtract allowable Oklahoma deductions on Schedule 511-B.

5. Calculate Your Oklahoma Taxable Income

Apply standard or itemized deductions using Schedule 511-C or 511-D.
Deduct $1,000 per exemption for 2020.
Use the official Oklahoma tax table to find your base tax amount.

6. Claim Credits and Report Payments

Include nonrefundable credits like the Credit for Taxes Paid to Another State (Form 511TX) or business-related credits from Form 511CR.
Enter refundable credits, such as the Sales Tax Relief Credit (Form 538-S).
Report any estimated tax payments made during the year.

7. Determine if You Owe or Get a Refund

Subtract total credits and payments from your tax owed.
If the result is negative, you have a refund. Choose direct deposit for the fastest processing.
If you owe, arrange payment promptly to avoid interest and penalties.

8. Review and Sign Your Return

Verify that all forms are complete and signatures are included.
Double-check figures and schedules for accuracy.
Keep copies of everything you file for your records.

9. Special Instructions for Nonresidents and Part-Year Residents

Complete Schedule 511NR-1 to determine the percentage of income taxable to Oklahoma. Follow instructions to prorate your tax liability accordingly.

10. Additional Steps for Small Business Owners

Transfer net profit or loss from your Federal Schedule C to your Oklahoma return.
Attach all related forms and documentation for business deductions and credits.
Confirm you meet the requirements for any corporate or small business credits you claim.

Filing Methods and Submission Guidelines

Oklahoma offers several ways to file your 2020 tax return, allowing you to choose the best method. The filing process can be completed electronically or on paper, but it is important to follow state guidelines to avoid delays.

Electronic Filing Options

OkTAP (Oklahoma Taxpayer Access Point)—Visit oktap.tax.ok.gov to file your return directly with the Oklahoma Tax Commission. This option is free for eligible taxpayers.
Commercial Tax Software—Many programs allow you to file federal and state returns together, often guiding you through each form.
Tax Professional—A certified preparer can file electronically on your behalf, verify your information, and help you find deductions or credits you might otherwise miss.

If you e-file, the deadline for 2020 returns was April 20, 2021, but payments must be made electronically by that date to avoid penalties.

Paper Filing Instructions

If you prefer to file by mail:

Download the necessary forms from the Oklahoma Tax Commission website.
Complete all required schedules and review for accuracy.
Sign and date your return.
Attach W-2s, 1099s, and related documentation.
Mail to the correct address:

If enclosing payment:

Oklahoma Tax Commission

Post Office Box 26800

Oklahoma City, OK 73126-0800

If expecting a refund or with no balance due:

Oklahoma Tax Commission

Post Office Box 269045

Oklahoma City, OK 73126-9045

Barcode Filing Option

If you prepare your return using approved tax software, you may be able to submit it with a 2D barcode. This allows the Tax Commission to process your return more quickly, reducing review time and helping you receive your refund sooner.

How to Make a Payment

The state offers multiple payment options if you owe Oklahoma taxes for the 2020 tax year. Choosing the correct method can help you avoid interest charges and ensure your payment is processed on time.

Electronic Payment Options

OkTAP (Oklahoma Taxpayer Access Point)—Pay directly through oktap.tax.ok.gov using an ACH debit from your bank account.
Credit or Debit Card – Payments can be made online; however, a convenience fee applies. This is useful if you need to pay quickly.
Direct Bank Withdrawal with E-File—When you file electronically, you can schedule your payment directly from your bank account on a specific date.

Check or Money Order

Make payable to “Oklahoma Tax Commission.”
Include the Form 511-V payment voucher with your return.
Write your Social Security Number, tax year, and “Form 511” on the payment.
Mail to:

Oklahoma Tax Commission

Post Office Box 26800

Oklahoma City, OK 73126-0800

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Payment Plan

If you cannot pay in full, you may qualify for an installment agreement with the Oklahoma Tax Commission. Contact their office directly to discuss terms. While a payment plan can help manage your balance, interest will continue to accrue until the full amount is paid.

Important Deadlines

April 15, 2021 – Standard payment deadline for the 2020 tax year.
April 20, 2021 – Extended deadline for electronic payments with an electronically filed return.
Paying 90% of your balance by the deadline minimizes penalties.

Tracking Your Refund or Balance Due

After you file your 2020 Oklahoma tax return, you can check your refund status or verify whether you still owe taxes. Tracking your return helps ensure it was received, reviewed, and processed without delays.

How to Check Your Refund Status

Online—Visit the Oklahoma Tax Commission’s website at tax.ok.gov and select “Check on a Refund.”
- Enter the last seven digits of your Social Security Number.
- Provide your ZIP code.
- Input the exact refund amount from your return.
Call (405) 521-3160 by phone and follow the automated prompts to check your refund directly.

Refund Timelines

E-filed returns—You can generally check your refund status within four days after the return is accepted.
Paper returns—Allow about three weeks before checking.
Direct deposit—Funds are typically available within five business days after processing.
Debit card – Expect delivery within 5–7 business days after processing.

Important Note

Oklahoma no longer issues paper refund checks. Refunds are sent either through direct deposit to your bank account or via an Oklahoma debit card if direct deposit information is not provided. If you still have a balance due, the Oklahoma Tax Commission website allows you to log in, review your account, and pay online to avoid further interest or penalties.

Extension Requests and Late Filing

The state offers an extension process if you need more time to file your 2020 Oklahoma tax return. However, an extension to the file does not extend the time to pay, and interest will still accrue on any unpaid balance. Filing on time—or paying enough to cover most of what you owe—is essential to minimize penalties.

Requesting an Extension

With a federal extension: Oklahoma will automatically extend your state filing deadline to match. If you have an approved federal extension
Oklahoma-Only Extension – File Form 504-I to request more time. You can download this form from the Oklahoma Tax Commission’s website.

Key Points to Remember

To avoid the late payment penalty, pay 90% of your expected tax by the original due date (April 15, 2021).
You must submit your return by the extended deadline to be considered on time.
Any unpaid balance after April 15 will accrue interest until paid in full.

Late Filing Penalties

If you fail to file by the due date (including extensions), Oklahoma may impose a penalty based on the amount of tax due. Penalties and interest are in addition to the balance owed and can increase your total payment over time.

Record-Keeping and Compliance Tips

Keeping accurate tax records is essential for verifying the information on your return and protecting yourself if your filing is reviewed. Record-keeping helps you find deductions, track payments, and respond quickly to state inquiries.

How Long to Keep Your Records

Minimum retention period—Keep copies of your tax return, forms, and supporting documents for at least three years from the later of the filing date or the due date.
Longer for special situations—Keep business and property-related records for five to seven years or until the asset is sold and the gain or loss is reported.
Indefinite retention—Store records permanently if they relate to non-taxable transactions or long-term assets.

What to Keep

Filed tax returns and all schedules.
W-2s, 1099s, and other wage or income documentation.
Receipts and invoices for deductions or credits claimed.
Bank statements or payment confirmations for any tax owed and paid.
Correspondence from the Oklahoma Tax Commission or IRS.

Compliance Tips

Review your return before submission to verify accuracy.
Store records in a safe, organized location—digital backups are recommended.
If you find an error after filing, submit an amended return as soon as possible to avoid additional interest or penalties.

Frequently Asked Questions

What if I missed the April 15, 2021, deadline?

If you missed the filing deadline, submit your return as soon as possible to reduce penalties and interest. You can still file using the correct forms for the 2020 tax year. If you expect to owe taxes, paying immediately will help limit additional charges. Consider filing for an extension next time to avoid late filing penalties.

Can I e-file my Oklahoma return for free?

Certain taxpayers are eligible to e-file their Oklahoma return at no cost through OkTAP, the state’s official online portal. Eligibility depends on factors such as income level and filing status. Visit the Oklahoma Tax Commission’s website to find out if you qualify and to access free filing tools. This is the fastest way to submit and receive your refund.

What are the most commonly missed deductions for Oklahoma taxpayers?

Commonly overlooked deductions include contributions to Oklahoma 529 College Savings Plans, donations to home-buyer savings accounts, and qualifying medical expenses not claimed federally. Other missed opportunities involve excluding interest on certain Oklahoma government bonds and deducting self-employed health insurance premiums. Reviewing the state’s deduction list before you file can help you find valuable savings. Always verify you meet eligibility requirements for each deduction claimed.

How do I request an extension for my Oklahoma tax return?

Oklahoma will automatically extend your state filing deadline to match if you already have a federal extension. For an Oklahoma-only extension, file Form 504-I before the original due date. Remember, an extension to the file does not extend the time to pay. Pay at least 90% of the tax you owe by April 15 to minimize penalties and interest charges.

I moved to Oklahoma mid-year. How do I file my taxes?

If you moved to Oklahoma during the year, file as a part-year resident using Form 511NR. Report all income earned while living in Oklahoma and any Oklahoma-source income earned as a nonresident. Use Schedule 511NR-1 to allocate income between Oklahoma and other states. This ensures you only pay tax on the portion related to Oklahoma. Keep all relevant records for verification.

What Oklahoma tax credits are available for small business owners?

Small business owners may qualify for credits such as investment in qualified businesses, job creation in certain areas, clean-burning fuel vehicle credits, and the credit for qualified software or cybersecurity employees. To claim these, complete Form 511CR and attach supporting documentation. Eligibility rules vary, so review them carefully before filing. These credits can help reduce your tax liability and encourage business growth.

If I earn income in multiple states, how is Oklahoma tax calculated?

Oklahoma residents must report all income, regardless of where it is earned, but may claim a credit for taxes paid to other states using Form 511TX. Nonresidents pay Oklahoma tax only on Oklahoma-source income. Keep detailed records of income from each state to ensure accurate reporting. This process helps prevent double taxation and ensures you pay the correct amount to each state.