The Internal Revenue Service requires businesses with employees to have an identification number known as the Employer Identification Number or EIN. The EIN for a business is similar to a Social Security number for an individual in that the number serves as a unique identifier for the business or person. Businesses report their EIN as part of their tax filings and you can use your employee tax records to find the EIN for your employer.

Obtain a copy of your latest W-2 form from your employer. The W-2 form, also known as a Wage and Tax Statement, is the information your employer provides to both you and the IRS to report your earnings and taxes for the year.

Check box "B" on your W-2; it's labeled Employer Identification Number. This box displays the EIN for your place of work.

Contact your human resources office if the EIN is not displayed on the W-2 form, or if you need a new copy of your form. Human resources can provide you an updated copy and can also provide the EIN for your workplace.