Conn. Gen. Stat. § 12-39dd

(b) (1) Each reporting entity shall file with the Department of Revenue Services, not later than thirty days after the reporting entity files information returns with the Internal Revenue Service, a duplicate of all such information returns, in such form and manner as prescribed by the commissioner.

(2) Any reporting entity that fails to file a duplicate information return required under subdivision (1) of this subsection within the time prescribed shall be subject to a civil penalty of (A) fifty dollars for each such failure if the failure is for not more than one month after such duplicate was required to be filed, and (B) an additional fifty dollars for each month or fraction thereof during which such failure continues, except the total amount of the penalty imposed on a reporting entity under this subdivision shall not exceed two hundred fifty thousand dollars annually. Subject to the provisions of section 12-3a , the commissioner may waive all or part of the penalties provided under this subdivision when it is proven to the commissioner's satisfaction that the failure to timely file such duplicate was due to reasonable cause and was not due to wilful neglect.