Colorado contractor licenses: three state licenses, then a patchwork of city rules

If you came from a state with one contractor board, Colorado will feel odd. The state does not license general contractors at all. It licenses a few trades, and then cities and counties decide what everyone else needs. That makes your service area the main question, not your trade. This page covers the three state licenses, then shows how two large local systems, Denver and the Pikes Peak region, work in practice. It reflects sources read in October 2026 and is general information, not legal advice.

Start with our Colorado startup page for entity and tax basics, and see the licensing boards by state table to compare with neighboring states.

What the state itself licenses

Colorado's Division of Professions and Occupations runs a State Electrical Board and a State Plumbing Board, and the Department of Agriculture licenses pesticide applicators. Outside those three, Colorado does not set a statewide license, so roofing, painting, general remodeling and similar work depend on local building departments. Heating and cooling follows the same pattern. The state's plumbing statute even carves air conditioning installations and heating appliances out of the plumbing license, and the cities, as the Pikes Peak mechanical classes below show, license mechanical contractors themselves.

Electricians: three license types and a homeowner exemption

Under C.R.S. § 12-115-109, nobody may work as a journeyman electrician, master electrician or residential wireman until licensed by the division or issued a temporary permit. The experience rules in § 12-115-110 set the paths:

• Journeyman: four years of apprenticeship or practical wiring experience, with at least two of those years in commercial, industrial or similar work, plus 288 hours of training in safety and the national electrical code in the last four years.
• Residential wireman: two years of accredited training or practical experience wiring one- to four-family dwellings. The license is marked across its face and does not authorize work beyond its type.
• Master: for example one year of practical planning and supervising experience beyond the journeyman requirement, or an engineering or trade-school route.

Renewals require 24 hours of continuing education, except at the first renewal after an exam. Check the division's electrical page for your own license's expiration date and renewal window.

Under § 12-115-116, a person may do electrical work on their own residence without a license if the work is inspected, but the exemption does not cover property intended for sale or resale by someone in the construction or remodeling business, rental property occupied by tenants, or property open to the public. The same section says cities and counties may not require their own electrician licensing or exams. They may require a reasonable registration of electrical contractors, with no fee. Colorado also issues electrical licenses by endorsement or reciprocity under § 12-115-113. See our electrician licensing guide for the national path.

Plumbers: licensed by the state, contractors registered by the state

C.R.S. § 12-155-108 prohibits working as a residential, journeyman or master plumber without a state license or temporary permit. A residential plumber may install plumbing in one- to four-family dwellings of no more than two stories above ground. The statute caps what the board may require to test at 3,400 hours of practical experience for residential, 6,800 for journeyman and 8,500 for master. Graduation from an approved plumbing program earns one year of credit. Apprentices must be registered within 30 days of starting work, and the employer is responsible for it.

A plumbing contractor must register with the board and either be, or full-time employ, a master plumber. A master can be responsible for only one plumbing contractor at a time. Cities and counties may license plumbing contractors on their own, but those contractors must also register with the state, and local rules may not block a state license holder from working.

Section 12-155-118 also lets owners do plumbing on their own property or residence, subject to the same limit on property built or remodeled for resale and on rentals. It says no plumbing license is required to install or maintain lawn sprinkler systems, water heating appliances, air conditioning installations or heating appliances, or to repair and replace garbage disposals, dishwashers, sinks, faucets, drains, showers, tubs and toilets. For a lawn care company that adds sprinkler repair, that is a rare state-level opening, but local permits and rules can still apply. Our plumber licensing guide covers the usual route elsewhere.

Pesticide applicators: a state fee schedule you can plan around

The Colorado Department of Agriculture licenses anyone who applies pesticides for hire. The commercial applicator business license is $350. The statute (C.R.S. § 35-10-106) requires a commercial business to employ or contract with a licensed qualified supervisor for the class of work it does, and individual licenses require a written exam in each class (§ 35-10-115). A limited commercial registration, for applicators who treat only property they or their employer own or lease, costs $50. The department sets individual license fees, so check its current schedule. If you run a lawn or pest route, budget for the business license and at least one qualified supervisor before the first treatment. Our pest control license guide has the national outline.

Denver: two steps, and nothing carries over

Denver's Community Planning and Development department says it does not accept or reciprocate contractor licenses or certificates from other counties or states. Licensing is a two-step process: first a supervisor certificate (or an employee who holds one), then the contractor license. A Colorado electrical or plumbing license can substitute for the supervisor certificate. Licenses and certificates renew every one to three years depending on type, and plumbing contractors must renew their state contractor card and master plumber card before they can renew the Denver license. Denver also issues right-of-way licenses for sidewalk, sewer, excavation and paving work, and offers a homeowner exam for owners acting as their own contractor. The licensing office is at 201 W. Colfax Ave.

Pikes Peak region: building classes A through F

The Pikes Peak Regional Building Department defines contractor classes in its regional building code. The ones most service businesses care about:

The department requires certificates of insurance naming it as certificate holder, general liability limits of $1,000,000 per occurrence and $2,000,000 aggregate for contractor categories listed, and a clause confirming re-roofing is not excluded. If you have employees you need workers' compensation proof, and if you have none, a Rejection of Coverage form. The state's Division of Workers' Compensation says businesses with employees in Colorado must carry coverage regardless of headcount.

Unlicensed trades and the tax side

For mowing, cleaning and pressure washing, the state sources reviewed show no statewide license, so the rules are local business licenses and any pesticide rules above. On tax, the Department of Revenue says Colorado generally taxes retail sales of goods, not services, with a short list of taxed services and a bundling rule for goods sold with services. The state rate is 2.9%, and some home-rule cities run their own sales tax systems. Our sales tax on home services by state table shows how this compares.

Working without the electrician or plumber license exposes you to penalties under C.R.S. § 12-20-407, the Division of Professions and Occupations' shared penalty section. Confirm local penalty rules with the building department, and confirm every point on this page with the agency named before you bid.

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