A water softener install changes the plumbing where the house water line enters the home. In many areas, that kind of connection falls under local plumbing or building rules, which can mean a permit, an inspection, or both. Rules differ by city, county, and water utility, so the reliable answer comes from your local building department. What you control is getting these questions answered before the crew arrives, not after the old pipe is cut.
Ask who pulls the permit
Ask the company directly whether it pulls permits for installations at your address or whether that job falls to you. Then ask the follow-up questions that matter: who is named on the permit application, what address and work description appear on it, and whether the permit number will be written on the paperwork you keep. A company that does this routinely should answer in a sentence. If the answer is vague, put the question in writing and get a written reply before you sign.
Find out when the inspection happens
Some jurisdictions want an inspector to see the new connection before walls, floors, or buried pipe cover it. Others only require a final check once the work is done. Ask the company which applies to your address and how the inspection fits into the install schedule. Then ask who books it, whether you need to be home, and what happens if the inspector flags something. Write down the answers. The sequence decides whether the crew has to come back and whether the system can go into service the same day.
Check the quote for permit fees and inspection time
Permit fees and inspection charges may appear as separate lines, be folded into the labor, or be left out entirely. When you compare written estimates, mark each one. Is a permit included? Who pays the fee? Is a re-inspection fee possible? Is a return visit for a failed inspection priced in? An estimate that leaves permit handling blank is not a lower price, just an unfinished one. Ask for the line to be written in before you accept.
Plan the electrical and drain-side work separately
If the install needs a new outlet near the unit, or the drain route changes, that work may need its own permit or a licensed electrician, depending on where you live. Ask the company whether any of the work falls outside its own license scope and who arranges that work. Do not assume one plumbing permit covers an electrical job.
Keep the paperwork once the job closes
When the inspection passes or the final check is signed off, ask for a copy of the permit with the final approval on it, or the written inspection result. Store it with the equipment manual and the installation invoice. You will want it if you sell the house, file an insurance claim, or need a future plumber to know what was changed at the water line. If a company cannot tell you where that paperwork goes, treat that as useful information before you choose it.
When you build your shortlist, the St. Louis company ratings can help you narrow the field, and then these permit questions can settle which company you hire.