Resident... Every resident individual whose gross income from both within and outside of Oklahoma exceeds the standard deduction plus personal exemption is required to file an Oklahoma income tax return. If you are uncertain about your filing requirement, see the charts on page 4. Resident individuals not required to file a federal income tax return must attach a completed federal income tax return to the Oklahoma income tax return to show how adjusted gross income and deductions were determined, if their gross income is more than their adjusted gross income. If you do not have a filing requirement, but had Oklahoma tax withheld, made estimated tax payments, qualify for the Natural Disaster Tax Credit or claim other refundable credits, you should file a return to get your refund.
Part-Year Resident... Every part-year resident, during the period of residency, has the same filing requirements as a resident. During the period of nonresidency, an Oklahoma return is also required if the Oklahoma part-year resident has gross income from Oklahoma sources of $1,000 or more. Use Form 511NR.
Nonresident... Every nonresident with gross income from Oklahoma sources of $1,000 or more is required to file an Oklahoma income tax return. Use Form 511NR