Sec. 9 Taxpayer — Publication 1516

Contractors are required to furnish taxpayer identification numbers (TINs) to the agency under section 6109 of the Internal Revenue Code. The agency must include the TIN of the contractor on Form 8596, Information Returns for Federal Contracts, pursuant to section 6050M(a)(1). The contractor’s TIN and name combination is used to associate information returns reported to the IRS with corresponding information on tax returns. It is imperative that correct social security numbers (SSNs) or employer identification numbers (EINs) for contractors are provided to the IRS. General guidance includes:

The TIN must be that of the contractor.
Don’t enter hyphens or alpha characters.
Don’t enter all zeros, ones, twos, etc., as this will result in an incorrect TIN.
The IRS validates the SSN by using the Name Control of the surname of the entity who has been assigned this number.
The issuer and payee names and TINs should be consistent with the names and numbers used on other tax returns.
If the contract is recorded in more than one name, the transmitter must furnish the TIN and name of one of the contractors.
The TIN provided must be associated with the name of the contractor provided in the First Payee Name Line of the Payee “B” Record.

The TIN for a sole proprietor may be either an EIN or SSN. The TIN to be furnished to the IRS depends primarily upon the way the account is maintained or set up on the agency’s record.