These links to other tax-related websites may be of additional help to you:

Official Payments Website (OPC)

The Internal Revenue Service

The Social Security Administration

PA Department of Revenue

Other States’ Tax Offices:

DCED: Pennsylvania Department of Community and Economic Development

PA Statewide Earned Income Tax Collectors & Rates (DCED tax register) 

PA Statewide Local Services Tax Collectors & Rates (DCED tax register)