How do I apply for an ITIN? Internal Revenue Service
The discussion of allowable tax benefits has been expanded. For more information see Allowable Tax Benefits in the Instructions for Form W-7 PDF. 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.
To apply for an ITIN, complete IRS Form W-7, IRS Application for Individual Taxpayer Identification