You have to file two state tax returns, a Georgia nonresident tax return and a South Carolina resident tax return. You have to pay Georgia tax on the income you earn in Georgia. Since you live in South Carolina, all your income is subject South Carolina tax, no matter where the income is from. But you will get a credit on your South Carolina tax return for part or all of the tax that you pay to Georgia. Prepare your Georgia nonresident tax return first, then your South Carolina resident tax return, to make sure that the credit is calculated correctly.
This applies to any year that you live in one state and work in another state, not just 2021.
