Country guide

United States

The United States mainly uses an SSN for most individuals, an ITIN for individuals who are not eligible for an SSN, an ATIN for a child in a pending U.S. adoption, and an EIN for businesses and other taxpayers that need a business tax identifier.

US USA 4 TIN types Last reviewed 2026-06-05

TIN types

4 published formats. Open a type to see examples, structure details, and official sources.

Validate United States TIN

United States Social Security Number (SSN)

Current Individuals

Social Security Administration (SSA)

Primary taxpayer identification number for most individuals.

Details

Examples

212-34-0001

Common names

SSN Social Security Number

Structure

1-3 Area number Three-digit number assigned by SSA. Under randomization, it no longer identifies a state.

4-5 Group number Two-digit number assigned by SSA.

6-9 Serial number Four-digit number assigned by SSA.

Official source

ssa.gov irs.gov

United States Individual Taxpayer Identification Number (ITIN)

Current Individuals

Internal Revenue Service (IRS)

Tax processing number for individuals who need a U.S. TIN for federal tax purposes but are not eligible for an SSN.

Details

Examples

900-70-0001

Common names

ITIN Individual Taxpayer Identification Number

Structure

1-3 Opening block Three-digit block in a nine-digit number formatted like an SSN and beginning with 9.

4-5 Range code Digits assigned within the IRS ITIN ranges.

6-9 Serial number Remaining digits assigned by the IRS.

Official source

irs.gov

United States Adoption Taxpayer Identification Number (ATIN)

Current Individuals

Internal Revenue Service (IRS)

Temporary taxpayer identification number for a child in a pending U.S. adoption when an SSN cannot yet be obtained.

Details

Examples

900-93-0001

Common names

ATIN Adoption Taxpayer Identification Number Taxpayer Identification Number for Pending U.S. Adoptions

Structure

1-3 Opening block Three-digit block in a nine-digit number formatted like an SSN and beginning with 9.

4-5 ATIN code Always 93 for an ATIN.

6-9 Serial number Remaining digits assigned by the IRS.

Official source

irs.gov

United States Employer Identification Number (EIN)

Current Individuals Entities

Internal Revenue Service (IRS)

Nine-digit identifier used for business tax accounts and other non-individual taxpayers. A sole proprietor may also obtain and use one when required.

Details

Examples

20-1234567

Common names

EIN Employer Identification Number Federal Tax Identification Number

Structure

1-2 Prefix Assignment prefix associated with an IRS campus or application channel.

3-9 Identifier Remaining digits assigned to the tax account.

Official source

irs.gov