Who Walks Through Your Door: Check Insurance, Licensing, and Crew Access Before You Commit

A water treatment installation puts someone in your utility room, under your sink, or beside your main water line for an afternoon or longer. Before you commit, the question is not only which equipment the company sells but who will be standing in your house and what stands behind them.

Ask for proof of insurance in writing

Ask the company to name its general liability insurer and send a current certificate of insurance. Ask whether the coverage extends to water damage caused during the work. Then ask who is named on the certificate, because a certificate for the company and a certificate for a subcontractor are different documents. If a plumber or electrician who is not on the company payroll will do part of the job, ask for that person's certificate too.

Confirm the license and what it covers

Plumbing and electrical work often require a license issued by a city, county, or state, and the rules differ from place to place. Ask for the license number of the person who will make the plumbing connection and look it up with the issuing office yourself rather than relying on a copy. A company may hold a license for one trade and subcontract the other, so ask which trade each person on the job is licensed for. If you are unsure what your area requires, the local building or licensing office can answer that question directly.

Ask who will be in the house

Ask how many technicians will visit, whether the same person will return for any follow-up, and whether anyone will work alone in a basement or crawlspace. Ask how crew members identify themselves at the door and whether they carry company identification. If you are not home during the work, ask whether they will enter, what they will touch, and whether they will leave a written summary of what was done that day.

Write the answers down before you sign

Get the answers in the proposal or a follow-up email, not just a phone call. Keep one sheet for each company you are comparing, with the insurer's name, the certificate, license numbers and the trades they cover, the names of any subcontractors, the main contact person, and what the company says will happen if the crew damages something in your home. Filling in the same sheet for every company makes gaps easy to see.

A list of award winners can help you build a shortlist, but it does not replace these checks. To understand how winners were selected before you treat any list as a guide, read the award methodology, then run the checks above on each company you consider.