Conn. Gen. Stat. § 4a-78: State policy with respect to providing Social Security numbers and federal employer identification numbers.

It is the policy of the state to require persons applying for a license, selling goods or services or leasing real or personal property to a public agency, to furnish a federal Social Security account number or federal employer identification number or both, if available, to establish the identification of persons affected by the tax laws of the state and for that purpose only to treat public agencies as having an administrative responsibility for the tax laws of the state.