How to Start a Plumbing Business in Michigan: Master Plumber and Plumbing Contractor Licenses

If you want to run a plumbing company in Michigan, the license comes first. Michigan has no general statewide business license, and plumbing is licensed by trade. LARA's Bureau of Construction Codes licenses plumbers under the Skilled Trades Regulation Act (2016 PA 407). That trade license is a different thing from the business filing you make with LARA's Corporations Division when you form an LLC or corporation. Confusing the two is the most common early mistake, and it can cost months.

This guide covers the path most owners take: apprentice registration, journey plumber, master plumber, and then the plumbing contractor license. It then covers the entity, tax and local steps that come after the trade credential. Use it as a checklist, and confirm each fee and deadline on the official page before you file.

Informational content, not legal or tax advice. Licensing rules, fees and deadlines can change. Confirm every figure with LARA, the Michigan Department of Treasury and your local building department before you act. For decisions about your business structure, tax position or liability, consult a qualified attorney or CPA.

What You Need Before You Start

Gather these items before you file anything. Most delays come from missing paperwork, not from the exam.

• Age verification. You must be at least 18 for both the journey plumber and master plumber licenses.
• Apprenticeship records. Dated time logs showing each employer, supervisor and hours worked. A journey plumber needs 6,000 hours over at least 3 years as a registered apprentice. A master plumber needs 4,000 hours over at least 2 years as a journey plumber, completed immediately before you apply.
• Exam plan. The journey plumber exam has a written part and a hands-on practical part. Check LARA for the current exam format, scheduling and any exam fee.
• Money for initial fees. The LARA application lists the initial license fees. This guide does not state them, so confirm the amount on the application before you budget.
• A business name. Search availability on the MiBusiness Registry before you commit to a name.
• A Michigan resident agent and registered office if you form an LLC or corporation.
• Insurance quotes. Ask your insurance agent what liability and workers' compensation coverage a plumbing contractor needs, and what your local jurisdiction requires. Requirements vary, so get them from the source.

Step-by-Step: From Apprentice to Plumbing Contractor

Step 1: Understand the four Michigan plumbing credentials

Michigan's plumbing credentials form a ladder, and each rung has its own requirements.

• Apprentice registration is the entry point for people learning the trade on the job.
• Journey plumber is the first full license. It is an individual credential.
• Master plumber is the next individual credential. It is for experienced plumbers who have completed the additional hours and passed the master exam.
• Plumbing contractor is the business-level credential under MCL 339.6111. You must hold a master license or employ a master plumber as your representative.

A licensed plumbing contractor is also exempt from the builder license for plumbing work only (MCL 339.2403(h)). That exemption does not cover other trades or general building work, so check your scope before you bid on a job that includes both.

Step 2: Register as an apprentice and log every hour

Register as an apprentice before you start counting hours toward journey plumber. Treat your time log as a formal record. Ask each supervising employer to sign off on hours monthly rather than at the end of the three years. Reconstructing months of work from memory is slow and often incomplete.

The three-year figure is a minimum. The 6,000 hours must be earned over at least that period, so you cannot compress the timeline by working more hours per week.

Step 3: Pass the journey plumber exam

The journey plumber exam has two parts: a written exam and a hands-on practical exam. Plan to pass both. Study the Michigan plumbing code that applies to your work, and practice the installations you perform every day. The practical portion rewards workmanship under time pressure. Check LARA for the current testing provider, content outline and rescheduling rules before you book.

Step 4: Earn the master plumber license

The master plumber license requires age 18 and 4,000 hours over at least 2 years as a journey plumber, completed immediately before you apply. The "immediately before" requirement matters. Hours you earned years ago, followed by a long break, may not count the way you expect. Ask LARA how it treats any gap before you set an application date. Then pass the master plumber exam.

Step 5: Decide how your contractor license will be held

A plumbing contractor license requires either that you hold a master license or that you employ a master plumber as your representative. Choose the structure before you form the business, because it determines who carries the license and who you must keep on staff.

• You hold the master license. You are personally qualified and can run the company yourself. The license depends on you, so plan coverage for illness, retirement or extended absences.
• You employ a master plumber as representative. You can own the company without holding the master credential yourself. The representative is an employee, so you carry payroll for that role, and the license depends on that person remaining in place.

Discuss this choice with an attorney or CPA, especially if you have partners or plan to sell the company later.

Step 6: Form the business entity

Your trade license belongs to you or to your representative. Your business entity is a separate filing with LARA's Corporations Division, and it does not make your plumbing company licensed. Think of it as the legal wrapper around the company.

• Sole proprietorship. There is no state entity filing. If you trade under a name other than your own, file a Certificate of Assumed Name with the clerk of each county where you do business under MCL 445.1. County fees are set by statute and by each county clerk, so confirm them locally.
• LLC. File Articles of Organization (Form CSCL/CD-700) with a $50 filing fee. The name must contain Limited Liability Company, LLC or L.C., with or without periods. Michigan calls the registered agent a resident agent, and it must be a Michigan resident or an entity authorized to do business in Michigan. A P.O. box alone is not sufficient for the registered office.
• Corporation. File Articles of Incorporation for Profit Corporation (Form CSCL/CD-500) with a $60 filing fee.

If your LLC operates under a trade name, file a Certificate of Assumed Name with LARA (Form CSCL/CD-541). The fee is $25 for an LLC and $10 for a corporation.

Search the name on the MiBusiness Registry before you file. If you need time to finalize a name, Form CSCL/CD-540 reserves it for six months following the month of filing, for $25.

If you need the filing done quickly, LARA offers expedited service under Form CSCL/CD-272, which is paid in addition to the filing fee:

Expedited option (formation or qualification documents)	Added fee
24-hour review	$50
Same-day review	$100
Two-hour same-day review (received by 3 p.m.)	$500
One-hour same-day review (received by 4 p.m.)	$1,000

Step 7: Register for taxes

Most plumbing companies need a federal Employer Identification Number from the IRS for payroll, bank accounts and tax filings. A sole proprietor with no employees may be able to use a Social Security number, but many owners get an EIN anyway. Then address the Michigan taxes that apply to your entity:

• LLC income. A standard LLC is a pass-through entity. Members report the income on the Michigan individual income tax at the flat 4.25% rate for the 2026 tax year.
• C corporation election. An LLC that elects federal C corporation treatment is subject to the 6% Michigan Corporate Income Tax. A small business alternative credit offers an alternate rate of 1.8% of adjusted business income. Ask Treasury whether you qualify.
• No franchise tax. Michigan imposes no franchise tax, and the only recurring LARA charge is the annual statement or report.
• Sales tax. If you sell taxable goods at retail, you must register with Treasury for a sales tax license. The registration is free and can arrive in as little as 7 business days. Confirm with Treasury how sales tax applies to your specific services and materials.
• City income tax. Only 24 Michigan cities levy a city income tax. If your business is located in one of them, confirm the local rule.

Step 8: Clear local permits and inspections

Your state trade license does not replace local permits. Permits and inspections are handled by the city, township or county building department where each job sits. Before you bid, ask that office which license holder must pull the permit, which inspections apply, what fees apply and whether the locality requires its own business registration. Michigan has 83 counties, roughly 275 to 280 cities, about 255 to 258 villages and 1,240 townships, so the answers change by jurisdiction. Get them in writing when you can.

Step 9: Submit the contractor license application

Apply through LARA once your credential and your structure for holding the license are settled. Check the LARA application for initial fees and required documents, since this guide does not state the initial fee. LARA does not publish a guaranteed standard review time for routine filings. Plan for variable timing, and do not promise a job start date until the license is in hand.

Step 10: Calendar renewals and annual filings

Plumbing renewals, as published by LARA for 2026, are due April 30 and carry a $100 late fee. Confirm the details on the LARA renewal page before you rely on them.

License	Renewal fee	Frequency
Master plumber	$300	Every 3 years
Plumbing contractor	$300	Every 3 years
Journey plumber	$40	Every year

Your entity has its own calendar. An LLC files an Annual Statement (Form CSCL/CD-2700) for $25 each year, due February 15, beginning the year after formation. An LLC formed or qualified after September 30 does not owe a statement on the February 15 immediately following. Professional LLCs pay $75 and face a $50 late fee after February 15, so confirm how your LLC is classified. A corporation files an Annual Report (Form CSCL/CD-2500) for $25 each year, due May 15. Late fees rise on a published schedule from $35 for May 16 to May 31, up to a $75 maximum on or after September 1.

Tips for a Smoother Path

• Start your hour log on day one of your apprenticeship, even if you are not thinking about licensing yet.
• Keep copies of every LARA confirmation, exam score and signed time record in one folder.
• Match your entity name, license holder name and trade name on invoices, contracts and permit applications so inspectors and customers can tie them together.
• Ask the local building department for its permit checklist before your first bid, not after.
• The Michigan Small Business Development Center offers counseling to small business owners. Check michigansbdc.org to see what it covers for your business.

Common Mistakes to Avoid

• Treating the LLC filing as a license. A successful entity filing makes the company legal to form. It does not license plumbing work.
• Counting hours without signatures. Hours without a supervisor's signature are hard to verify, so keep every log signed.
• Taking a long break before the master application. The requirement is 4,000 hours completed immediately before you apply, so plan your timing.
• Assuming the state license covers every permit. Local permits and inspections are separate, and each jurisdiction sets its own rules.
• Using a P.O. box as the registered office. A P.O. box alone is not sufficient.
• Missing renewal dates. Plumbing renewals are due April 30 and carry a $100 late fee. An LLC Annual Statement is due February 15.

What Results to Expect

If you work through these steps in order, you may be able to bid on plumbing work under your own company name. The timeline depends on your apprenticeship hours, exam scheduling, LARA processing and local permit requirements. Many owners find that the experience requirement takes longer than the paperwork. Treat any timeline you see here as an estimate, and build a buffer into your launch plan.

Official Resources

• LARA Corporations Division: https://www.michigan.gov/lara/bureau-list/cscl/corps
• MiBusiness Registry (name search and online filing): https://mibusinessregistry.lara.state.mi.us/
• Michigan Department of Treasury: https://www.michigan.gov/taxes
• Treasury business registration: https://www.michigan.gov/taxes/business-taxes/new-biz/online-business-registration
• Michigan Small Business Development Center: https://michigansbdc.org/
• Plumbing licensing: LARA Bureau of Construction Codes, through michigan.gov/lara

Because these rules involve statutes, tax treatment and personal liability, confirm your plan with a qualified attorney or CPA before you form the business or sign a contract.