What kind of work requires a license
Whether you need a license depends on what you are fixing and where you live. Some work is restricted by law to licensed professionals; other work you can do yourself. The rules vary significantly by state and even by city, so your location matters as much as the job itself.
Work that almost always requires a license includes electrical wiring, plumbing that connects to the main water line or sewer, HVAC system installation and repair, and gas line work. These systems can cause serious injury or property damage if done wrong, so states regulate who can touch them. A few states also require licenses for roofing, and some cities require permits and licensed contractors for any structural work.
Work you can usually do yourself includes painting, drywall repair, replacing cabinet hardware, fixing doors and windows, replacing light fixtures (as long as you do not rewire), and most appliance maintenance. The key distinction is whether the work affects safety systems or connects to the home's main utilities.
Key Takeaways
- Electrical, plumbing, HVAC, and gas work require a licensed contractor in nearly every state, and doing it yourself can void your homeowner's insurance.
- Your state's contractor licensing board website lists which trades require licenses and what the requirements are for each one.
- Even if you can do the work yourself, your city may require a permit and a licensed contractor to pull it, which means you cannot avoid licensing entirely.
- Hiring an unlicensed contractor can leave you liable if someone is injured and exposes you to fines from your city or county.
- Some states allow homeowners to do electrical or plumbing work on their own property if they pull a permit and pass inspection, but the rules differ widely.
How to find out what your state requires
Start with your state's contractor licensing board. Most states have one agency that oversees all licensed trades—search "[your state] contractor licensing board" or "[your state] department of professional regulation." The board's website lists which trades require licenses, what training and exams each trade needs, and whether homeowners can do the work themselves.
If your state's board does not have a clear answer, call your city or county building department. They issue permits and know which work requires a licensed contractor before a permit will be issued. Building departments are usually more restrictive than state law, so if the state allows homeowner work, your city might still require a licensed contractor.
Keep in mind that licensing rules change, and some states have recently loosened or tightened requirements. The information on the board's website is your most current source.
Electrical work and when you can do it yourself
Most states do not allow homeowners to do any electrical work beyond changing outlets or light bulbs. Running new circuits, upgrading a panel, installing a new outlet, or rewiring anything requires a licensed electrician in nearly every state.
A small number of states—including some parts of California, Florida, and a few others—allow homeowners to do electrical work on their own single-family home if they pull a permit and have the work inspected. Even in those states, the rules are strict: you usually cannot do the work if you plan to sell the house soon, and the inspector may require you to prove you understand the code. Check with your local building department before assuming this is an option.
Hiring an unlicensed electrician or doing the work yourself when it is not allowed can cause your homeowner's insurance to deny a claim if there is a fire or injury. It also exposes you to fines from your city.
Plumbing, HVAC, and gas work
All three of these trades require a licensed contractor in every state. You cannot do plumbing work that connects to your main water line or sewer, install or repair an HVAC system, or touch a gas line yourself, even on your own property.
The reason is straightforward: mistakes in these systems can cause gas leaks, carbon monoxide poisoning, water damage, or sewage backup. Inspectors are required to verify the work meets code before it is hidden behind walls or underground.
Some states allow homeowners to do very minor plumbing work—replacing a faucet, unclogging a drain with a snake—but anything that requires cutting into a pipe or connecting to the main line needs a licensed plumber. If you are unsure whether your job crosses that line, call a plumber for a five-minute phone consultation rather than guessing.
Roofing and structural work
Roofing requirements vary by state. Some states require a licensed roofer; others allow homeowners to roof their own house. Check your state's contractor board first, then confirm with your city, because many cities require a licensed roofer even if the state does not.
Structural work—anything that affects the frame, load-bearing walls, or foundation—almost always requires a licensed contractor and a permit. This includes adding a wall, removing a wall, installing a beam, or repairing foundation cracks. Structural mistakes can make a house unsafe and unsellable.
Permits and inspections even when you hire a contractor
Even if you hire a licensed contractor, your city may require a permit before the work starts. Permits are not optional—skipping one can result in fines, problems when you sell the house, or denial of an insurance claim.
The contractor you hire should know whether a permit is required and should pull it as part of their job. If they say "we do not need a permit," that is a red flag. Ask your building department directly whether the work requires a permit, and if it does, make sure the contractor pulls it before they start.
Inspections happen after the work is done. An inspector from your city checks that the work meets code. This protects you: if something goes wrong later, you have proof that a licensed professional did the work correctly and an inspector signed off on it.
What happens if you hire an unlicensed contractor
Hiring an unlicensed contractor puts you at risk in several ways. If someone is injured on your property, you may be liable. If there is a fire or other damage caused by the work, your homeowner's insurance may deny the claim. Your city can fine you for allowing unlicensed work, and you may have to pay to have the work redone by a licensed contractor to bring it up to code.
When you sell the house, a home inspector or appraiser may flag unpermitted or unlicensed work, which can kill the sale or force you to disclose the problem and lower your price. It is not worth the short-term savings.
Frequently Asked Questions
Can I do electrical work myself if I pull a permit?
In most states, no—a permit does not give you permission to do the work yourself. A few states allow homeowners to do electrical work on their own home with a permit and inspection, but this is rare. Check your state's contractor board and your city building department to know for sure.
What if the contractor says they do not need a permit?
Call your building department and ask directly whether a permit is required for that type of work. If it is, do not hire the contractor. Unpermitted work can cause problems when you sell and may not be covered by insurance if something goes wrong.
Do I need a license to replace a faucet or light fixture?
No. Replacing a faucet, light fixture, or outlet does not require a license in any state. If the work involves cutting into pipes or running new electrical circuits, that is different—those jobs need a licensed professional.
What if I live in a state that allows homeowner electrical work?
You still need to pull a permit and have the work inspected. The permit process is how the city verifies you did the work safely. Do not skip it, even if you are allowed to do the work yourself.
Can I hire a contractor who is licensed in another state?
No. Licenses are issued by individual states and are not transferable. A contractor must be licensed in your state to legally do the work. Check your state's contractor board to verify a contractor's license before you hire them.