A Federal Employer Identification Number is used by the Internal Revenue Service to identify a business entity. These identification numbers are issued by the IRS and are also sometimes referred to as Federal Tax Identification Numbers.
The IRS requires Employer Identification Numbers to be issued to any business that has employees or operates as a corporation or partnership. Businesses that file an employment, excise, or alcohol, tobacco and firearms tax return are also required to apply for an identification number. Businesses already issued an identification number that have changed ownership or restructured most likely need to apply for a new number. Small business that do not meet any of these conditions are not required to apply for a number.