The post is incorrect. There is no tax credit and you are entitled to a refund of your entire NJ withholding. Pennsylvania residents employed in New Jersey are not subject to New Jersey Income Tax.
If New Jersey Income Tax was withheld by mistake from your wages, you must file a New Jersey nonresident return to get a refund. Adjust your NJ income to $0 on the NJ tax form to get the full amount back.
Enclose a signed Statement of New Jersey Nonresidency, which is available on at njtaxation.org. See “Employee’s Certificate of Nonresidence in New Jersey” under Individual Income Tax Forms.
To stop the withholding of New Jersey Income Tax, complete a New Jersey Employee’s Certificate of Nonresidence in New Jersey (Form NJ‑165) and give it to your employer.
For detailed instructions see Pennsylvania Residents on page 31.
