Plumbing is heavily licensed. Research your state plumbing board's license levels, whether the company needs a master plumber of record, local registration, and which work requires permits and inspections, such as water heaters, new lines and gas piping. Backflow testing can require separate certification.
What to check
| Item | Where |
|---|---|
| Plumbing license | State plumbing board |
| Business registration | State and local |
| Permits | Local building department |
| Backflow tester | State or local certification |
| Gas piping | May need separate license |
Questions for the building department
- Does a water heater replacement need a permit?
- Who can pull permits?
- What inspections are required?
Who to ask and what to ask
| Office | Question |
|---|---|
| State plumbing board | What license does the business need, and what work does each license allow? |
| Building departments | Which jobs need permits and inspections? |
| Water utility | Are backflow testing certifications required? |
| Gas authority | Who may work on gas piping? |
| Insurance agent | What do property managers require? |
Backflow and gas work
Many water utilities require certified testers for backflow prevention devices on commercial and irrigation systems, and gas piping often needs specific licensing or permits. These certifications open steady recurring work, such as annual backflow tests, but they come with paperwork deadlines to track.
Sample permit flow for a water heater replacement
Pull the permit before the work, as your jurisdiction requires. Install the new heater to the manufacturer's instructions and local code, including the temperature and pressure relief valve discharge, venting for gas units, seismic strapping in areas that require it, and an expansion tank where required. Schedule the inspection, keep the permit number in the job file, and register the warranty. Inspectors commonly check venting, gas connections, relief valve piping and clearances.
Mistakes that cause problems
- Working on gas lines without the required license
- No permits on changeouts
- Expired backflow tester certification
- Letting apprentices work without required supervision
Rules owners often miss
Plumbing licenses usually cap what each license level may do, and some local jurisdictions require separate registration before you pull permits there. Keep a list of where you are registered and renewal dates.
What to research
| Requirement | Usually handled by |
|---|---|
| Plumbing license (master/journeyman/contractor) | State plumbing board or local licensing |
| Business registration | State and local |
| Permits for installs and repairs | Local building department |
| Backflow certification (if offered) | State or local program |
Free tools
Common questions
Who can pull plumbing permits?
Usually a licensed plumber; rules vary.
Is backflow testing separate?
Often requires certification.
Do I need a gas license?
Gas piping may require separate licensing in some places.
Does a water heater replacement need a permit?
In many jurisdictions, yes. Check with your local building department.
Do plumbers need continuing education?
Many states require it for license renewal.
Who can install gas water heaters?
Many places require licensed plumbers or gas fitters and permits; check local rules.
Sources
Sources checked October 6, 2026. Rules, fees and forms change; confirm details with the agency or provider before you act. This guide is general information, not legal, tax or insurance advice.
Check your domain and prepare your business information
Once your name is settled, check that the domain is free and keep your legal name, phone and address consistent. Your domain is included when we build your website. Start with the free checklist.
Check domain and website options