What is the tax withholding rule concerning an employee who is a resident of Delaware working in Pennsylvania?

In the situation you have described, the Delaware resident is required to have Pennsylvania taxes withheld. Pennsylvania and Delaware do not have tax reciprocity.

Disclaimer: The above Question and Answer are for informational purposes only. Any tax advice provided in this communication is not intended or written by the author to be used, and cannot be used by the recipient, for the  purpose of avoiding penalties which may be imposed on the recipient by the IRS or State or Local taxing authority. Please contact a board Certified Public Accountant (CPA) for advice relating to your specific situation.