Once you become a CT resident, all your income becomes taxable by CT, and NJ can only tax income you earn from work actually performed within NJ.
So if you move to CT and never physically work in NJ after the move, then you would only need to withhold CT taxes.
But if you move to CT and physically work in NJ after the move, then - depending on how significant your earnings are from NJ - you may need to withhold only NJ taxes. That's because your earnings from work carried out in NJ will be taxed by NJ, but you'll be able to claim a credit on your CT tax return for the tax you pay to NJ on the income taxed by both states.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
