What happens if you do electrical or plumbing work without a license?

This question gets asked from two directions: tradespeople tempted to take side jobs before they're licensed, and homeowners wondering if the license rules apply to their own house. The consequences are real in both cases, but they land very differently — and the most expensive ones aren't the fines.

For the unlicensed worker

For the homeowner who hires unlicensed

What homeowners can legally do themselves

Most states have a homeowner exemption: you can perform electrical or plumbing work on your own primary residence, usually with a permit and inspections, sometimes after a homeowner test, and typically with restrictions (no rentals, no properties for sale, sometimes limits on service panels or gas lines). The exemption covers you working on your house — it does not let an unlicensed friend do it for money. Rules vary widely; your local building department's website is the authoritative source.

Where the line actually is

ScenarioGenerally legal?
Apprentice working under a licensed supervisor, registered, on the employer's jobsYes — that's the system working
Homeowner rewiring own primary residence with permit, where exemption existsUsually yes, with conditions
Replacing a faucet, light fixture, or other like-for-like maintenanceCommonly exempt — check local rules
Apprentice taking paid side jobs without supervisionNo — this is the classic violation
"Handyman" quoting electrical/plumbing beyond the state's minor-work thresholdNo — thresholds are low and enforced
The system is the point. This site exists because licensing makes these trades durable careers — the legal monopoly on permitted work is precisely what protects licensed tradespeople's wages from being undercut. If you're doing the work anyway, the rational move is to get the hours registered and the license earned. Start with your trade and state in our guides.