Conn. Gen. Stat. § 12-50: List may be filed by spouse, attorney or agent.

The list of taxable property required to be filed annually by any taxpayer may be filed by the husband or wife or by an authorized agent or attorney of a taxpayer. Such husband or wife or agent or attorney shall make oath that he is authorized by the taxpayer to file such list and that he has knowledge of all taxable property of his principal subject to taxation in the town or other municipality wherein such list is filed.