Here's a couple of references on that topic:
https://www.americantraveler.com/state-tax-questions
and http://www.thegypsynurse.com/tax-home/
The general rule is: your report all your income on your home state return, even the income earned out of state. You file a non-resident state return for the state you worked in and pay tax to that state. Your home state will give you a credit, or partial credit, for what you paid the non-resident state. You will have to file a non resident SC state return and pay SC tax on the income earned there.. You will also file an OK full year resident return and calculate tax on ALL your income. OK will give you a credit, or partial credit, for the tax you pay SC. So, there will be little or no double taxation. Do the nonresident state return first.
