Can you install a water heater for a neighbor on a Saturday without a license? In most of the country, the honest answer is no — and it's not the plumbing part that gets side-workers in trouble, it's the permit. Plumbing is one of the most tightly licensed side trades there is, and the rules trip people up in a specific, predictable place.
The three-rung ladder, and where side work actually sits
Nearly every state runs plumbers through the same basic ladder: apprentice, journeyman, master. An apprentice works under direct supervision while logging hours. A journeyman has usually put in 4,000 to 8,000 hours — often a full four years — through a registered apprenticeship, then passed a trade and code exam. That license lets you work plumbing jobs independently in most states.
Here's where it gets specific to your side business: a journeyman license, on its own, generally does not let you pull permits or run your own plumbing business. That's typically reserved for a master plumber license, which requires another one to three years beyond journeyman plus a harder exam. Master status is also usually what's required to legally operate as a contractor — the person whose name is on the permit application and who's accountable to the inspector.
| Rung | Typical requirement | Can run a business / pull permits? |
|---|---|---|
| Apprentice | Registered apprenticeship, logging hours | No |
| Journeyman | 4,000–8,000 hrs + exam | Usually no |
| Master | Journeyman + 1–3 yrs + harder exam | Usually yes |
A few states genuinely don't require a state-level plumbing license at all — Kansas, Nebraska, and Wyoming are the commonly cited examples. But "no state license" doesn't mean "no license anywhere." Cities and counties in those states routinely license plumbers on their own, and a permit is still usually required for the work itself. Skipping the state step doesn't skip the local one.
The mistake that actually costs people money
Most articles on this stop at "check your state," which is true but not useful — it doesn't tell you what actually goes wrong. The real trap is the journeyman assumption: a lot of side-working plumbers hold a valid journeyman license, correctly believe they can legally do the work, and then take on a job that needs a permit — assuming their license covers pulling it. In most states, it doesn't. The permit has to be pulled by a master plumber or a licensed contractor, and if that's not you, the job either needs a master to sign on, or it needs to happen under someone else's permit with their knowledge and consent — never quietly, and never without them knowing work is happening under their license.
Take a real ticket: a water heater install. According to SideWRK's rate report, a typical water heater install runs around $1,600, with roughly 60% of that as labor — call it $960 in skilled labor and $640 in the unit and fittings. That size and scope is exactly the kind of job most jurisdictions require a permit and inspection for, because a bad water heater install is a flood-and-carbon-monoxide risk, not a cosmetic one. A $125 service call to unclog a drain almost never needs a permit. A $1,600 water heater swap almost always does. Same trade, very different paperwork obligation, and the dollar amount is a decent rough proxy for which side of that line a job falls on.
What actually protects you, permit or not
None of this is legal advice, and the specific answer for your city and license status is something only your state board or city building department can give you — rules vary enough state to state, and even city to city within a state, that a general guide can't safely tell you "you're fine" or "you're not." What a general guide can tell you is what to do regardless of where you land on the ladder.
Document everything. If you're doing work at your license level — a drain clearing, a faucet swap, a leak repair — put it on a real invoice with the job scope, the parts used, and any disclosure notes ("old galvanized line left in place at customer request," for example). If a job needs a permit and you're not the one pulling it, get that arrangement in writing before the wrench touches the pipe, not after. None of this replaces a license you don't have. It's the difference between a side business with a paper trail and one that's one bad afternoon away from a real problem — the records your state requires, kept somewhere better than a shoebox.
Building toward master status
If you're a journeyman running side work and permits keep being the ceiling on what jobs you can take, that's usually a sign it's worth logging the hours toward master status on purpose rather than by accident. Track which jobs you turned down or handed off because of the permit line — that list is a good proxy for how much business a master license would actually unlock, versus how much it'd cost in hours and exam fees to get there.
In the meantime, price and document the jobs you can legally do at full value. SideWRK's plumber trade page sets up estimates and invoices with plumbing's real job types and rates already built in, and the free invoice generator is a fast way to see what a properly itemized invoice should include if you're still deciding on a full setup. If licensing is the thing standing between you and more work, the math is usually clearer once you can see, job by job, what you're turning away. Locksmiths deal with a similar patchwork of state-by-state rules — worth a look at how locksmith licensing varies by state if you're weighing a second trade alongside plumbing.
FAQ
Do I need a license to do plumbing side work?
In almost every state, yes — plumbing is one of the most consistently licensed side trades, typically requiring at minimum a journeyman license to work independently. A handful of states (Kansas, Nebraska, Wyoming among them) have no state-level requirement, but cities and counties in those states often license plumbers locally, so "no state license" rarely means "no license needed at all."
Can a journeyman plumber start their own side business?
Usually not fully. A journeyman license typically lets you perform plumbing work independently, but pulling permits and legally running your own plumbing business is generally reserved for a master plumber license in most states — a distinction that trips up a lot of side-working journeymen who assume their license covers both.
Does a water heater install need a permit?
In most jurisdictions, yes. A water heater install is a common example of a job that requires a permit and inspection because of the flood and carbon monoxide risk if it's done wrong — unlike a smaller job like a drain clearing or faucet swap, which usually doesn't.
What happens if I do plumbing work without the right license?
Consequences vary by state and city but can include fines, being barred from pulling future permits, and no legal recourse if a customer disputes the work or refuses payment. Check your specific state licensing board and city building department before taking on any job that needs a permit.
How long does it take to become a master plumber?
After becoming a journeyman — which itself typically takes 4,000 to 8,000 hours through a registered apprenticeship — most states require another one to three years of experience plus a harder exam to reach master status. Total time from apprentice to master commonly runs five to seven years, depending on the state.
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