Employers must apply for and obtain a federal Employer Identification Number (EIN) from the Internal Revenue Service (IRS). The EIN is an employer's account number for the collection and reporting of taxes withheld and wages paid to the employees.
Your EIN will be a nine digit-number that takes the form: 12-3456789. It is assigned to sole proprietors, corporations, partnerships, estates, trusts, and other entities for filing and reporting purposes. All partnerships, corporations, and trusts need an EIN, even if they have no employees. Sole proprietors generally need one only if they have employees, have a Keogh pension plan, or must pay certain federal excise taxes.
Applying for an EIN. To get an EIN, complete and submit application SS-4 to the IRS. We suggest that you do this before you open for business so that you will have it ready when the first taxes must be deposited. File only one Form SS-4, regardless of the number of businesses operated or trade names under which a business operates.
If you become the owner of an existing business. Do not use the EIN of the former owner. If you already have an EIN, use that number. If you do not have one, apply for one using Form SS-4. There's an exception to this general rule: if you become the owner of a business by purchasing stock, use the business's EIN.
Household employers. Household employers are also required to complete Form SS-4 to get an EIN, even if your only employees are household employees (such as domestic workers like maids, nannies, drivers, etc.) in your private home.
State and local EINs. Be sure to get any state or local EINs that may be required.