An Employer Identification Number (EIN) is a nine-digit number issued by the IRS. An EIN identifies the tax accounts of employers and certain other taxpayers, and determines the type of business tax return they must file.
An EIN is typically issued in the following format: XX-XXXXXXX. Sometimes, a letter or an employee plan number (for example, 003) may follow the EIN.
When you enter your wages into TaxAct, you will need to enter the EIN of your employer.
See Entering in Program - Form W-2
Contact your employer if you have any questions related to the EIN that appears in Box (b) on your W-2.