As of July 1, 1999, the State of Connecticut Department of Consumer Protection per public act 99-174.SB 959 requires a license for swimming pool maintenance.

 DON'T BE FOOLED between a Registered and a Licensed contractor. There are a lot of companies claiming to be fully licensed. Unless they have an SP before or after their number chances are they may only be a registered contractor and not a licensed contractor. 

What is the difference? 

SP1 and SP2 licenses are issued by the Department of Consumer Protection under the authorization of the State Plumbing Board. Proof of EXPERIENCE and INDUSTRY TRAINING was required to initially receive a SP1 and SP2 licenses occurring grandfathering which has since expired. A TEST is now required for new applicants and yearly state approved continuing education is mandatory for all. Registration Numbers are given out by the State to companies doing work over a certain dollar value, No testing or education is required.