How to Start a Plumbing Business in Illinois: IDPH License and Contractor Registration

Starting a plumbing business in Illinois requires you to navigate both state and local licensing requirements. Unlike many business structures, plumbing is a regulated trade in Illinois. If you plan to perform plumbing work for pay in Illinois, you must first obtain an individual plumber license from the Illinois Department of Public Health (IDPH), then register as a plumbing contractor, carry the right insurance, and post a bond. This article walks you through the exact steps and costs involved.

What You Need Before You Start: The Materials List

Before you file any paperwork, gather these essentials:

• An IDPH individual plumber license, the foundation of everything else. You cannot register as a contractor without one.
• $150 per year, the annual contractor registration fee with IDPH. This is not optional; every contractor must renew it before September 30 each year.
• Proof of a $20,000 indemnification bond or letter of credit, required by IDPH. This protects customers if something goes wrong. You'll post this before registration.
• General Liability (GL) insurance, minimum $100,000 per occurrence and $300,000 aggregate, plus $50,000 property damage coverage.
• Workers' Compensation insurance, minimum $500,000 employer's liability (if you have employees). If you operate solo with no employees, you may qualify for an exemption, but confirm with IDPH.
• Federal Employer Identification Number (EIN), from the IRS, even if you're a sole proprietor with no employees.
• Illinois tax registration, through the Illinois Department of Revenue, free and online via MyTax Illinois at https://tax.illinois.gov/.
• Local business license or permit, many counties, cities, and villages in Illinois require their own local business license on top of state registration. Check with your local government.
• If you operate in Chicago, a separate Chicago plumbing contractor license ($150 per year) and $20,000 bond. Chicago has its own Board of Plumbing Examiners and licenses all contractors independently, even those already registered with IDPH.

Step 1: Obtain Your IDPH Individual Plumber License

Before you can register as a contractor, you must hold an active Illinois plumber license from the Illinois Department of Public Health. This license is issued to an individual who has met training and examination requirements. The IDPH website details the pathways to licensure, which typically include hands-on apprenticeship or equivalent work experience, classroom training, and a state exam. You will need to verify the current exam fees, application timeline, and documentation requirements directly with IDPH, as these details change. Visit the Illinois Department of Public Health website at https://www.dph.illinois.gov/ to start the application process. Confirm the current requirements, exam schedule, and any fees before submitting your application.

Step 2: Gather Bonding and Insurance Documentation

IDPH contractor registration requires two separate protective documents. First, obtain a $20,000 indemnification bond or letter of credit from a bonding company or your bank. The bond is filed on an IDPH form and covers work performed under the Illinois Plumbing License Law and its rules. The cost depends on the bonding company; shop around for quotes. Second, secure the required insurance coverage:

• General Liability: $100,000 per occurrence, $300,000 aggregate, $50,000 property damage
• Workers' Compensation: $500,000 employer's liability (waivable if you have no employees; confirm the waiver rules with IDPH)

Contact insurance brokers who work with trade contractors. Plumbing is a recognized trade, so you should find competitive rates. Have certificates of insurance ready to upload when you register.

Step 3: Apply for Federal Tax Registration (EIN)

Apply for a Federal Employer Identification Number (EIN) from the IRS, even if you're operating as a sole proprietor with no employees. This is your tax ID and is required for most business structures. You can apply for free at https://www.irs.gov. The process is instant online. Save your EIN for the next steps.

Step 4: Register with the Illinois Department of Revenue

Illinois imposes no single general statewide business license, but you must register with the Illinois Department of Revenue for tax purposes. This is free and takes one to two business days online. Use MyTax Illinois at https://tax.illinois.gov/ (Form REG-1) to register. You will provide your business name, structure, EIN, and planned activities. If you plan to collect sales tax (not typically required for service-only plumbing, but verify for your scope), you will receive a Certificate of Registration. Many cities and counties require you to show this certificate when applying for local permits.

Step 5: File Your IDPH Plumbing Contractor Registration

Once you have your IDPH plumber license, bonding, and insurance in place, file the annual plumbing contractor registration with IDPH. This registration names you (or a licensed plumber of record if you structure the business differently) and requires renewal every year before September 30. The registration fee is $150 per year. Late renewal carries a penalty and may result in suspension of your registration. You must submit:

• Your active IDPH plumber license
• Proof of the $20,000 indemnification bond or letter of credit
• Certificates of insurance meeting the requirements above
• The $150 registration fee

Submit these materials to IDPH. Confirm the current submission process and mailing address or online portal at the Illinois Department of Public Health website. Keep copies of your registration for your records and for any future renewals.

Step 6: If You Operate in Chicago, Obtain a Chicago Plumbing Contractor License

Chicago maintains its own plumbing licensing system through the Chicago Board of Plumbing Examiners. If you work in Chicago, Illinois, regardless of your IDPH registration, you must also hold a Chicago plumbing contractor license. Chicago accepts IDPH plumber licenses as the foundation, but requires every contractor to register locally. The Chicago license costs $150 per year and requires a $20,000 indemnification bond separate from your IDPH bond. This is a duplicate bonding and licensing requirement; many state-registered contractors find it redundant but it is mandatory in Chicago. Apply through the Chicago Department of Buildings, which oversees the Board of Plumbing Examiners. Confirm current fees and application procedures with the city.

Step 7: Obtain a Local Business License or Permit

Many counties, cities, and villages in Illinois require their own local business license on top of state registration. Contact the county clerk's office and your city or village hall to ask whether a local business license or contractor permit is required in your jurisdiction. Some localities require renewal annually; others charge a one-time fee. These vary widely and are not overseen by the state, so you must check locally.

Materials Summary: Total Startup Costs

Here is a rough estimate of first-year costs (confirm all fees locally):

• IDPH plumber license exam and application: Verify current fee with IDPH
• $20,000 indemnification bond or letter of credit (IDPH): premium set by the bonding company
• General Liability insurance: premium varies by carrier and claims history
• Workers' Compensation insurance: premium varies, if you have employees
• IDPH contractor registration: $150 per year
• Chicago plumbing contractor license (if applicable): $150 per year plus a $20,000 bond
• Local business license: set by each locality
• Illinois tax registration: Free
• EIN application: Free

Total first-year costs depend on bonding and insurance quotes and your local jurisdiction. Budget for insurance quotes from multiple carriers.

Tips to Avoid Common Mistakes

• Do not skip the IDPH plumber license. It is the prerequisite for everything else. You cannot legally work as a plumbing contractor without it.
• Renew IDPH contractor registration before September 30 every year. Late renewal can result in suspension. Set a calendar reminder.
• If you work in Chicago, do not assume IDPH registration is enough. You must also register with the Chicago Board of Plumbing Examiners and maintain a separate Chicago license and bond.
• Verify bonding and insurance requirements locally. This article reflects state requirements, but some localities add stricter minimums. Confirm with your city or county.
• Shop around for bonding and insurance. Quotes vary widely. Do not accept the first quote; get three to five and compare.
• Keep current documentation on file. IDPH may request proof of bonding or insurance at any time. Losing a certificate or letting coverage lapse can trigger suspension.
• Understand the apprentice pathway. If you are not yet licensed, confirm the apprenticeship requirements and timeline with IDPH. The state licenses apprentice plumbers and plumbers; it has no separate statewide journeyman or master plumber license.
• Do not confuse contractor registration with business structure. Whether you operate as a sole proprietor, LLC, or corporation, you must still complete these licensing steps. Business structure is separate and is handled through the Illinois Secretary of State.

Expected Results

Once you complete these steps, you will be legally authorized to perform plumbing work in Illinois under your IDPH plumber license and contractor registration. Customers can verify your license through IDPH's online license lookup. You will have met state insurance and bonding requirements, which protects both you and your customers. If you operate in Chicago, you will also be registered with the city. Annual renewal of your IDPH contractor registration is straightforward, submit the $150 fee and updated insurance and bonding documentation before September 30.

Your business is now positioned to bid on jobs, hire and manage employees (if applicable), and operate legally. If you already hold an IDPH plumber license, registration mainly depends on how quickly you gather the bond and insurance certificates. Earning the plumber license itself takes much longer, since it follows an apprenticeship and the state exam. Plan accordingly if you have a target start date.

Important Disclaimer

This article provides informational guidance on Illinois plumbing licensing requirements as of October 2026. It is not legal advice, tax advice, or a substitute for consulting with a qualified attorney or accountant. Licensing rules, fees, and insurance requirements change. Verify all current requirements directly with the Illinois Department of Public Health (https://www.dph.illinois.gov/), your local health department or city licensing office, the Chicago Board of Plumbing Examiners (if you operate in Chicago), and the Illinois Department of Revenue (https://tax.illinois.gov/). If you have complex questions about business structure, liability, or tax treatment, consult a qualified professional in your area.

Next Steps

Contact the Illinois Department of Public Health to confirm current requirements and exam schedules. Reach out to bonding companies and insurance brokers for quotes. Check your local city or county for any additional business license requirements. Consider consulting with a small business advisor or attorney familiar with Illinois plumbing regulations, especially if this is your first time starting a business or if you plan to hire employees.