How to start a plumbing business: a practical guide for licensed plumbers

Most plumbers who go out on their own are already good at the work. What catches them out is everything around it: a license that covers plumbing but not contracting, an insurance certificate the license board wants on file, a first month of quotes priced too low, and invoices nobody chases.

This guide is for a licensed journeyman or master plumber in the US going solo. It follows the order you'll need things in and links the official source for every government rule. Rules change and differ by state, so treat it as a checklist to confirm, not legal or tax advice.

Step 1: Find out which license lets you contract

Plumbing licensing in the US is set state by state, and in some places by the city. The license that lets you work on pipes is often not the same thing as the license that lets you sign your own contracts with customers. Here is how four places handle it, checked against each agency's own pages:

The pattern is the same almost everywhere: experience, an exam, proof of insurance, often a bond, and a fee. The details are not. Before you print business cards, find your state's plumbing board or contractor board, and ask your city or county whether they license plumbers too. If you plan to work across a state or city line, check both sides.

Fees, amounts and requirements above were checked on the agencies' websites on October 6, 2026. Confirm them with the agency before you apply.

Step 2: Pick a business structure and get an EIN

The two common choices for a solo plumber are a sole proprietorship and an LLC. The SBA puts the difference plainly: as a sole proprietor you can be held personally liable for the business's debts and obligations, while an LLC protects your personal assets, such as your house and savings, in most cases. LLC members are still considered self-employed and pay self-employment tax. Plumbing can damage other people's property, which is why many plumbers choose an LLC. A local accountant can tell you which is better for your taxes.

Then get an Employer Identification Number (EIN). The IRS says you need one if you have employees or operate as a partnership, corporation or LLC, among other cases, and banks often ask for one anyway. It's free and issued online in minutes at IRS.gov. The IRS warns that you never have to pay a fee for an EIN, so skip the websites that charge for one.

While you're at it:

• Open a separate business bank account. Every job payment goes in, every business expense comes out. Your bookkeeping and taxes get much easier.
• Register with your state and city. Depending on where you are, that can mean a state business registration, a local business license, or a sales tax account.
• Choose a name you can keep. Before you pay for a truck wrap, check that the name is available in your state's business registry, that the website address is free, and that your license board allows it.

Step 3: Get insured, and bonded where required

Insurance is often a licensing requirement, not just good sense. Texas wants $300,000 of commercial liability coverage on file for the RMP designation; Washington wants $200,000/$50,000 or $250,000 combined; NYC requires general liability, workers' compensation and disability insurance for every Master Plumber business.

• General liability covers damage or injury you cause on a job. The SBA describes it as protection against financial loss from bodily injury, property damage and lawsuits.
• Workers' compensation becomes a must when you hire. The SBA says businesses with employees are required to have workers' compensation, unemployment and disability insurance, and that state rules vary.
• Your truck. Ask your agent whether your personal auto policy covers a vehicle used for work. Don't assume it does.

A bond is different from insurance: it protects your customers and the state if you don't meet your obligations. California requires a $25,000 contractor bond (raised to that amount on January 1, 2023), and Washington a $6,000 surety bond. Some cities and counties ask for a bond before they'll issue permits. Check what your state and the places you'll pull permits require.

Step 4: Set your prices before the first call

The fastest way to fail with a full schedule is to price from what your old shop charged or what the cheapest guy online charges. Your costs are different now: you pay for the truck, the insurance, the phone, the hours you spend quoting and driving, and your own salary.

1. Work out your hourly price from a year of costs, your salary and the hours you can actually bill. Our guide to how to price plumbing jobs has the math and a worked example.
2. Set your service call fee and decide whether you credit it toward the job. See how to set a plumbing service call fee.
3. Write down a materials markup rule so every quote uses the same one.
4. Turn your 20 most common jobs into flat rates: faucet swap, toilet rebuild, water heater replacement, drain clearing. That list is the start of your plumbing price book.

Step 5: Set up how you quote and invoice

On your own, the paperwork happens at night unless you build a routine. Keep it simple and the same every time:

1. Quote in writing, every time. List each line, what's included and what isn't, and how long the price is good for. Our plumbing estimate template is a free starting point.
2. Check before you send. Permit, shutoff valves, expansion tank, haul-away, after-hours fee. The items you forget are your margin. The water heater quote checklist shows how many there are on one common job.
3. Get approval in writing before you start, with a signature or at least a written yes.
4. Take a deposit on big jobs, especially when you're buying expensive equipment up front.
5. Invoice the same day the work is done, from the approved quote, and record how and when you were paid. The plumbing invoice template shows what to include.

Plumbo, now on the App Store and Google Play, is built for this loop: say the job, answer only what's missing, and it builds the quote from your own price book, checks it for forgotten items, and turns the signed quote into an invoice in one tap. Try the 60-second demo →

Step 6: Get your first customers

You don't need a big marketing budget to start. You need people who already trust you to know you're on your own, and a way for strangers to find you.

• Tell everyone you've done good work for, along with friends, family and neighbors. Ask them to pass your number on. Respect any non-solicitation agreement you signed with your old employer.
• Set up a Google Business Profile. Plumbers are a service-area business: Google's help center says that if you don't serve customers at your business address, you should remove the address and enter only your service area. Be specific about the area you really cover.
• Ask for reviews after every job that went well, while the customer is still happy.
• Talk to people who send plumbing work: property managers, general contractors, remodelers, realtors and home inspectors. Reliability and fast quotes win these relationships more than price.
• Get known at your supply house. Counter staff hear who's looking for a plumber.

Step 7: Protect your cash flow

Profitable plumbing businesses still run out of cash. Materials get paid before the customer pays you, and taxes come due whether or not the last invoice cleared.

• Collect when the job is done. For residential work, payment at completion should be the default, not net 30.
• Use deposits on jobs with expensive equipment, so you aren't financing the customer's water heater.
• Set aside money for taxes from every payment. The IRS says sole proprietors and partners generally have to make estimated tax payments if they expect to owe $1,000 or more when they file. Ask your accountant what share to set aside.
• Open an account at your supply house once you can. Payment terms give you time between buying parts and getting paid.
• Look at your numbers every month: what you invoiced, what you collected, what's still owed, and what you spent.

How much does it cost to start a plumbing business?

Less than most people fear in fees, more than they expect in insurance. The government part is usually a few hundred dollars. The ongoing part, insurance, the truck and your tools, is what decides how much cash you need before the first invoice is paid. Here are the published numbers we could check, and the lines only you can fill in:

Insureon figures are medians for plumbing contractors who applied for quotes through Insureon (fewer than five employees, five years or less in business), not quotes. Your price depends on your state, claims history, payroll and limits. Government fees were checked on each agency's website on October 6 and 13, 2026.

Worked example: a solo plumber in Texas (example numbers)

A Master Plumber in Texas who forms an LLC and gets the RMP designation pays $300 to the Secretary of State, $225 to the plumbing board and $0 for the EIN: $525 in fees. At the Insureon medians, general liability ($147) plus commercial auto ($285) plus tools coverage ($42) comes to $474 a month, or $5,688 for a year. Add your truck, tools, stock, phone and a first round of marketing from your own numbers, and keep two or three months of those running costs in the bank: early customers don't always pay on day one.

The useful habit is to turn that monthly total into a number you charge. Divide your monthly costs, including the salary you want to pay yourself, by the hours you can really bill, and you get the floor under your hourly rate. Our guide on how to price plumbing jobs walks through it step by step.

A one-page plumbing business plan

You don't need a 30-page document unless a lender asks for one. You do need answers to these, written down:

• Services: what you'll do (service and repair, water heaters, repipes, new construction) and what you won't.
• Area: the towns or ZIP codes you'll cover, which also drives your service call fee.
• Customers: homeowners, property managers, contractors, or a mix.
• Costs and prices: your yearly costs, your hourly price and your service call fee.
• Start-up list: truck, tools, license and insurance costs, and the cash you'll need before money comes in.
• Target: how many jobs a week you need to cover your costs and your salary.

The short version

Get the license that lets you contract in your state and city. Pick a structure, get a free EIN and a separate bank account. Carry the insurance and bond your license requires, and workers' comp when you hire. Price from your own costs from the first call. Quote in writing, check before you send, invoice the same day. Tell everyone you're open, and keep enough cash to get through a slow month.

Sources

• Texas State Board of Plumbing Examiners, Responsible Master Plumber (eligibility, $300,000 commercial liability insurance, $225 initial fee), checked October 6, 2026.
• Texas State Board of Plumbing Examiners, Master Plumber (work under the supervision of a Responsible Master Plumber), checked October 6, 2026.
• Contractors State License Board, C-36 Plumbing Contractor (classification), checked October 6, 2026.
• Contractors State License Board, Before applying for the examination (four years' experience, $1,000 threshold), checked October 6, 2026.
• Contractors State License Board, Bond requirements ($25,000 since January 1, 2023), checked October 6, 2026.
• Contractors State License Board, List of all CSLB fees ($450 original application, $200 or $350 initial license fee), checked October 13, 2026.
• Texas Secretary of State, Form 205 instructions, Certificate of Formation for an LLC ($300 filing fee), checked October 13, 2026.
• Insureon, Plumbing business insurance cost (median monthly costs and method; updated August 5, 2026), checked October 7, 2026.
• Washington State Department of Labor & Industries, Plumbing contractor licensing requirements (bond, insurance, designated plumber, fees), checked October 6, 2026.
• NYC Department of Buildings, Obtain a Master Plumber License (experience, exams, required insurance), checked October 6, 2026.
• U.S. Small Business Administration, Choose a business structure, checked October 6, 2026.
• U.S. Small Business Administration, Get business insurance, checked October 6, 2026.
• IRS, Employer identification number and Get an employer identification number, checked October 6, 2026.
• IRS, Estimated taxes, checked October 6, 2026.
• Google Business Profile Help, Manage your service areas for service-area & hybrid businesses, checked October 6, 2026.