Key takeaways IRS Form SS-4 is used to obtain an Employer Identification Number (EIN) for your business or other entity such as a trust or estate. The SS-4 form requires detailed information about ...

You can either apply by fax, mail or online. If you apply by fax or mail, you must fill out and submit the IRS Form SS-4. If you need your EIN number fast, you can apply online.

What is an EIN? An employer identification number or EIN — a type of federal tax identification number or TIN — is what the IRS uses to identify companies. Business owners use an EIN for any related ...