Tax ID

What is a Tax ID?

A Tax ID, or Taxpayer Identification Number (TIN), is a unique number the IRS uses to identify a business or individual for tax administration purposes. The most common form used by businesses is the Employer Identification Number (EIN), a nine-digit number the IRS assigns to a company, trust, or other entity. Individuals typically use a Social Security Number (SSN) or, for those not eligible for an SSN, an Individual Taxpayer Identification Number (ITIN).

For procurement and supplier data teams, a vendor’s Tax ID is a core identifier collected through Form W-9 before payments are issued. Matching the Tax ID against IRS records and cross-referencing it across systems helps confirm supplier identity, prevent duplicate or mismatched vendor records, and support accurate 1099 reporting.