It all depends on where you actually (physically) work. If you work remotely from a PA location for an AL employer, then you're physically working in PA.
If you're a resident of PA and you never physically work within Alabama, then you have no income tax obligation to the State of Alabama.
However, Alabama can tax any income you make from work you physically perform within Alabama. In that circumstance you would have to file an NR Alabama return, declaring the portion of your income that you earned in Alabama. If you're a PA resident, ALL your income is taxable by PA, regardless of where you earn it. You will be able to claim an "other state credit" on your PA tax return for any income tax that you may have to pay AL. The credit prevents double taxation, which is prohibited by federal law.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
