Use this site to check if your contractor is a registered Home Improvement Contractor.
On this site you can verify the status of a license issued by Division of Standards (DOS) or the Division of Occupational Licensure (DOL), Office of Public Safety and Inspections. You can also download a data file of your search results at no cost.
Use Check a Commonwealth Licensee to see if a business or individual has a valid license or permit.
This site has information and resources on registering as a home improvement contractor.