EIN vs. Tax ID: what's the difference?

The terms get used interchangeably, which causes most of the confusion. 'Tax ID' (or TIN. Taxpayer Identification Number) is the umbrella category: any number the IRS uses to identify a taxpayer. An EIN is one kind of TIN, the kind that identifies a business entity.

The three TINs you'll actually encounter

SSN. Social Security Number. Identifies an individual person. Sole proprietors without an EIN use their SSN as their business tax ID.

ITIN. Individual Taxpayer Identification Number. Issued to individuals who need a U.S. tax ID but aren't eligible for an SSN, commonly non-resident individuals with U.S. tax obligations.

EIN. Employer Identification Number. Identifies a business entity: LLC, corporation, partnership, trust, estate, or nonprofit.

So when a form asks for your 'tax ID'…

If the form is about the business, a W-9 for your LLC, a business bank application, payroll setup, it wants the EIN. If it's about you personally, it wants your SSN. A federal tax ID and an EIN are the same thing when the taxpayer is a business.

One more term you may see: 'state tax ID.' That's separate, some states issue their own numbers for state taxes like sales tax or unemployment insurance. The EIN is federal and doesn't replace state registrations.

Need the business kind? We prepare and file EIN applications for a $99 service fee, while the IRS charges $0 and lets you apply free at irs.gov.