Conn. Gen. Stat. § 4b-101

The commissioner of each state agency authorized to contract for the construction or alteration of buildings under section 4b-1 or 4b-51 shall provide to the Commissioner of Revenue Services a complete list of all contractors and subcontractors doing work on any such construction or alteration project, if available, and the contractors' and subcontractors' (1) Connecticut tax registration numbers and (2) federal Social Security account numbers or federal employer identification numbers or both, if available, before making final payment on the project.