How Do I Find My Tax ID Number : U.S. Taxpayer Identification Numbers

How Do I Find My Tax ID Number : U.S. Taxpayer Identification Numbers

U.S. taxpayer identification numbers include a Social Security Number (SSN), which is issued to individuals, and an Employer Identification Number (EIN), which is issued to individuals or entities. In addition, an Individual Taxpayer Identification Number (ITIN) is issued to individuals who are required to have a U.S. taxpayer identification number but who do not have and are not eligible to obtain an SSN.


A taxpayer must provide the taxpayer identification number (SSN, EIN or ITIN) on all tax returns and other documents sent to the IRS. A taxpayer must also provide its identification number to other persons who use the identification number on any returns or documents that are sent to the IRS. An SSN is issued to individuals by the Social Security Administration.

Further information regarding the SSN may be found at: An EIN is issued by the IRS to sole proprietors, partnerships, corporations (including limited liability corporations), and other entities for tax filing and reporting purposes.

Application for an EIN may be made by either:

(1) submitting IRS Form SS-4, Application for Employer Identification Number ( online; or

(2) mailing or faxing the Form SS-4 as described in the form instructions.

How Do I Find My Tax ID Number :

The U.S. Taxpayer Identification Number may be found on a number of documents, including tax returns and forms filed with the IRS, and in the case of an SSN, on a social security card issued by the Social Security Administration. In the United States, TINs are generally considered confidential, private identity information.

When provided to the IRS, TINs are protected from disclosure under section 6103 of the Code; and, in some cases, section 6105 of the Code in conjunction with confidentiality provisions of the relevant tax treaty, tax information exchange agreement, or other bilateral agreement for the exchange of information, when the information is provided to the IRS by a foreign government under such treaty or agreement.

TIN Structure

An SSN is in the following format: xxx-xx-xxxx. The first three digits have geographical significance, the next two digits have no real significance and are issued sequentially, and the last four digits are random.

An EIN is in the following format: xx-xxxxxxx.

An ITIN is a nine-digit number that always begins with the number 9 and is in the following format:


TIN Number Format

Do I Need One?

A TIN must be furnished on returns, statements, and other tax related documents. For example a number must be furnished:

  • When filing your tax returns.
  • When claiming treaty benefits.

A TIN must be on a withholding certificate if the beneficial owner is claiming any of the following:

  • Tax treaty benefits (other than for income from marketable securities)
  • Exemption for effectively connected income
  • Exemption for certain annuities

Taxpayers with specific individual or business account questions should contact the International Taxpayer Service Call Center by phone or fax. The International Call Center is operational Monday through Friday, from 6:00 a.m. to 11:00 p.m. (Eastern Time):

Tel: 267-941-1000 (not toll-free)

Fax: 267-941-1055