New entity filing forms are available on the "Initial Forms" tab. Several state agencies are working together to allow you to establish a Keystone ID which creates a single way to access several different state programs.Filling out this registration form requires careful consideration of various sections. This form allows the employee to verify that the employer is withholding the correct tax rates for the correct municipalities. Instructions on how to register for income or unemployment tax in Pennsylvania. The easiest way to sign up for the SAT is to register online. Before you register, make sure you have a photo and form of payment. Completing this form will NOT fulfill the requirement to register for corporate taxes. Registering corporations must contact the. A vehicle registration form is the official form that vehicle owners must fill out before registering a motor vehicle.