If you have one or more employees (not including yourself), or if you are a partnership or corporation with or without employees, the first thing you must do is obtain a Federal Identification number* for federal and Massachusetts tax purposes.
Sole proprietorships without employees (other than the owner) which are required to file excise, alcohol, tobacco, firearms or employment tax returns, must also obtain a federal employer identification number.
Other sole proprietorships without employees (other than the owner) can use their Social Security number as their federal business identification number.
Please note that a husband and wife running a business together (with or without employees) are considered a partnership, not a sole proprietorship, and must obtain a federal employer identification number.
Federal employer identification numbers can only be obtained from the Internal Revenue Service (IRS). To obtain a Federal Identification number, applicants must file federal Form SS-4, Application for Employer Identification Number, apply online or apply over the telephone. For details, visit the IRS website and refer the instructions for Form SS-4.
*The Federal Identification number is sometimes also referred to as a federal employer identification number; an employer identification number; or a business identification number.