A Taxpayer Identification Number (TIN) is an identification number used by the Internal Revenue Service (IRS) in the administration of tax laws. It is issued either by the Social Security Administration (SSA) or by the IRS. A Social Security number (SSN) is issued by the SSA whereas all other TINs are issued by the IRS.

http://www.irs.gov/businesses/small/international/article/0,...

sau Tax Identification Number / Tax ID

What is a Tax Identification Number?

Tax ID numbers, also called an Employer Identification Number (EIN), is a special identifying number assigned solely to businesses by the IRS. Your tax ID number is used to identify your business to several federal agencies responsible for the regulation of business, both Online and Offline.

Many merchant accounts, banks and other financial institutions require a tax ID in order to utilize their services. Tax ID’s can also keep your social security information private as many institutions who request tax ID’s will also accept personal social security and banking information as an option (which has to be used unless the business has a tax ID).

http://www.ecommerceoptimization.com/articles/starting-out-g...

consumer affairs number [Canada]
tax identification number [United States]
federal tax ID number [United States]
Tax ID number [United States]
Tax number [United States]
IRS number [United States]
IRS Number

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