2. He’s Dodging the Details

A responsible plumber will be glad to provide their proof of insurance, plumbing license number, and any other credentials you may ask to see to validate their competence and legal standing. Moreover, most plumbers have this information on their business cards, websites, and other marketing materials.

If a plumber is hesitant to show you their credentials or comes up with excuses for why they can’t, that’s definitely a warning sign that you’re about to hire someone shady. In fact, if the plumber shows you their license number only after you’ve insisted on seeing it, it may be because the license isn’t in good standing.

Pro Tip: Head over to your state’s Contractors State License Board to check if your plumber’s license is valid.