reciprocity NJ-Philadelphia

When all else fails, read the instructions:

Who must file?
Any PA resident, nonresident or part-year resident
who:
• Received total PA gross taxable income in
excess of $33 during the tax year, even if no
tax is due; and/or
• Incurred a loss from any transaction as an
individual, sole proprietor, partner in a partnership or PA S corporation shareholder

NJ taxes all income of NJ residents.

You don't need to file Philadelphia if tax withheld = tax owed.

You may need to file PA though, unless NJ and PA have a reciprocal arrangement. That I don't know.

IF the employer did it right, there should be no PA income tax because of the reciprocity compact. No PA return is needed for this job, except to get refunded PA income tax improperly withheld.

NJ resident, in-Philadelphia employee, needs to file NJ COJ to claim credit against NJ tax. Be aware that Philly wages are usually higher than NJ wages, so you might not claim 100% of wage tax as a credit.

IE, city taxes 401k deferral while NJ does not, so city wages are higher than NJ wages.