I receive my paycheck from PA but do not live or work in that state yet. May relocate soon. Should they be deducting PA taxes from my check?

I would say no, for example for 4 years I worked for a company that was based in FL, But I worked only in TN and normally worked out of my home. So they only withheld TN taxes.

And likewise, they had employees in every state in the union and they held out the taxes for the state they were working in, not the place where the home office was located.

So if you are working in another state ( you did not say where you were living and working) if you do work for them in another state, and are based out of that state, your taxes should be from that state.

If you are considered based out of PA and that is where your job is normally located, and you are only temp in another state, they could be holding PA taxes since that is where they consider you employed at.

Agree, though I am curious how they withheld TN taxes when TN has NO state income tax!