Koen plumbing moved drain lines for my tub and shower. They did not get a permit for this work. The city of Dallas requires a permit for this type of work. Lack of a permit could lead to a denial of a claim by our insurance company if there was ever an issue ( burst pipes from a winter for example ) When I called the plumber who did the job - he outright admitted to me on a phone call that they frequently don’t pull permits even if the work requires it unless the homeowner explicitly asks. I discovered the issue after the work had been covered up and Koen charged me to uncover it. If you hire for anything other than repairing a leak them make sure to check that they get a permit. Also don’t let them try to tell you it is a big inconvenience. Permits are $100, the inspectors come the next day and the plumber does not have to be present.