What is Employer Identification Number (EIN)?
An EIN is a nine-digit federal tax ID for a business — essentially a Social Security number for your company.
How it works
You apply on IRS.gov and usually get one instantly. You need it to hire employees, open a business bank account, file business returns, and often to work with vendors who'd otherwise need your personal SSN.
A quick example
What people get wrong
Getting an EIN is free and takes minutes on IRS.gov. Ignore third-party sites that charge a "filing fee" — they're just reselling a free government service.