Here are some invaluable tax forms for payroll and contractor payments. Please check to make sure a form is the latest version before you start using it.
For contractors, freelancers, and anyone else who might receive Form 1099 at the end of the year
The W-9. This gives you your vendor’s tax ID number and address, both necessary for the 1099.
For payroll
The W-4. All employees must fill this out to choose their federal income tax withholding.
The I-9 or Employment Eligibility Verification form, which attests to the employee’s citizenship/immigration status.
The M-4, which is Massachusetts’s version of the W-4.
A direct deposit form (here’s an example, with generation loss, from ADP). Do get a canceled check from your employee to make absolutely sure that you enter the correct bank information into your payroll system.