Conn. Agencies Regs. § 14-137-61
For the purpose of assessment of a late fee for renewal of motor vehicle registration in accordance with subsection (z) of section 14-49 of the Connecticut General Statutes, a registration renewal application that is properly completed and signed and includes payment of the proper fee shall be considered submitted in a timely manner if received by the department not more than five (5) calendar days after the scheduled expiration date of the registration period.
(Effective January 7, 1992; Amended June 1, 2015)