How to Start a Plumbing Business in Kentucky

The Master Plumber Requirement Comes First

You cannot legally operate a plumbing contracting business in Kentucky without an active master plumber serving as the designated technical qualifier. The state does not issue a standalone "plumbing contractor license" to a business — instead, every plumbing contracting entity must employ or be owned by a licensed master plumber. If you hold a journeyman license, you need to upgrade to master before launching your own operation.

If you are the master plumber, you can serve as your own qualifier. If you plan to run the business side while someone else handles the trade work, you must employ a master plumber and file a Letter of Representation with the DHBC naming them as your qualifying agent.

Register Your Business Entity

Kentucky plumbing businesses must establish a business structure. If you choose an LLC or corporation, register it with the Kentucky Secretary of State's office. Your options:

• Sole proprietorship — simplest structure, but offers no personal liability protection.
• LLC — separates personal assets from business liabilities. Most plumbing contractors choose this structure for the liability shield and tax flexibility.
• Corporation (S-Corp or C-Corp) — more formal governance requirements, but can offer tax advantages depending on revenue levels.

For an LLC or corporation, registration is filed online through the Secretary of State's business portal. You will also need a Commonwealth Business Identifier and a state tax account through the Kentucky Department of Revenue.

File the Letter of Representation

Once your business is registered, the qualifying master plumber must sign and file a Letter of Representation with the DHBC Division of Plumbing. This document formally links the master plumber's individual license to the business entity, authorizing the company to contract plumbing work and pull permits.

If the qualifying master plumber ever leaves the company, you must immediately file a Letter of Dis-Representation. Without a qualifying master on record, the business cannot legally contract, pull permits, or advertise plumbing services. A 180-day grace period exists only in the case of the qualifying master's death, allowing the business to complete outstanding projects while finding a replacement.

Insurance and Bonding

Kentucky requires three types of coverage for plumbing contractors:

General liability insurance — minimum $250,000, though many general contractors and municipalities require $1,000,000 for commercial projects. The insurance certificate must name the DHBC as the certificate holder.

Workers' compensation insurance — mandatory if you employ even one person. Kentucky law requires this coverage within 10 days of hiring your first employee. Operating without workers' comp can trigger stop-work orders and fines up to $1,000 per day.

Surety license bond — $10,000, guaranteeing compliance and performance of permitted operations.

Local Business Licenses

Kentucky does not have a statewide general contractor license, so local requirements vary significantly. In Louisville, you need a Type A ($125/year) or Type B ($50/year) contractor registration plus a Jefferson County occupational tax account. In Lexington, state-licensed plumbers register with LFUCG at no cost but still need a $100 business license.

Smaller cities and counties may have their own occupational license requirements. Check with your county clerk's office before beginning operations.

Get an Accounting System in Place

The state verifies employee experience through W-2 records during license audits. If you are supervising apprentices or journeymen, your payroll records serve as their proof of qualifying experience — sloppy recordkeeping can block their future license applications and create headaches for your business.

Set up proper payroll withholding, issue W-2s consistently, and keep records long enough to support license audits and your employees' qualifying-experience claims.

The Kentucky Plumber License Guide covers the full business setup process — from filing the Letter of Representation to securing insurance certificates in the exact format the DHBC requires.

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