Nolo’s Plain-English Law Dictionary. Gerald N. Hill, Kathleen Thompson Hill. 2009.
Taxpayer ID Number / taxpayer identification number (TIN)USAAn identification number used by the IRS in the administration of federal 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. A TIN must be furnished on returns, statements, and other tax related documents.A TIN may be any of the following:• SSN. An individual may have an SSN. If the individual does not have, and is eligible for, an SSN, he or she must use Form SS-5 to apply for an SSN. The SSA will tell the individual if he or she is eligible to get an SSN.• Individual taxpayer identification number (ITIN). An individual may have an ITIN. If the individual does not have, and is not eligible for, an SSN, he or she must apply for an ITIN by using IRS Form W-7.• employer identification number (EIN). Any person other than an individual, and any individual who is an employer or who is engaged in a US trade or business as a sole proprietor, generally must have an EIN. Use IRS Form SS-4 to apply for an EIN.
Practical Law Dictionary. Glossary of UK, US and international legal terms. www.practicallaw.com. 2010.