@Opus 17 is correct. If SC is your primary residence (your domicile in tax terminology), then ALL your income is taxable by SC, regardless of where you earn it. The fact that your employer failed to withhold SC taxes from your pay does not relieve you from your SC tax obligation.
Other states with an income tax can tax you as a non-resident on income "sourced" to that state, such as earnings from work you perform within that state's borders.
Therefore at tax time you must file both a non-resident Ohio tax return reporting all the income you earned in Ohio, and a resident SC tax return reporting all your income, including that from Ohio.
You'll be able to claim an "other state credit" on your SC return for the taxes you pay to OH on the income taxed by both states. The credit prevents double taxation, which is prohibited by federal law.
With TurboTax, you should complete the non-resident state tax return before the home state tax return. The program will then calculate and apply the credit for you.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
