The person who signs a W-9 must be a U.S. person, an individual who is a U.S. citizen or a U.S. resident alien. The signer should have the organization’s consent to sign a W-9 on its behalf.
IRS Form W-9 is most commonly used by individuals when they are working as a freelancer or independent contractor.
If you ever find yourself filling out a Form W-9, it generally means a business or person who is paying you money needs your U.S. Taxpayer Identification number (TIN)–which can be the U.S. Social Security Number (SSN), Individual Taxpayer Identification Number (ITIN), or Federal Employer Identification Number (EIN/FEIN)–so the business/person can notify the IRS of the amount.
Minors: In the case of a minor, the W-9 should be completed with the minor’s name and the minor’s Taxpayer Identification Number (TIN) since they are the owners of the payment being made. The signature can be either the minor’s signature or the legal guardian’s (parent or court appointed legal guardian). A minor cannot sign a contract, but the W-9 is not a contract. The W-9 is just giving the name and TIN of the minor, therefore a legal guardian is not required, but is only encouraged.