General construction contractors in Colorado are not licensed by the state. You should check for license requirements at the local level. Electrical and plumbing contractors require a license to work in the state.

Nielsen Mechanical Contractors Inc currently holds license CL-006733-2025, AEC6789, 0016081, LIC-00997071, AEC9665, 100927, E190339, LCC201800753, AEC3195, 12740423-5501, MA01058, LIC-0007512, EC.0100927, 0003867, 25-000619, CL-006712-2025, 17-2585, AEC000400, AEC000367, 0015565, CON-21-0172, LIC-0007512-GENCC, GCC3575139, 101031039, 060831041, CON-17-0079, AEC6312 (General, Contractor, Unlimited, Mechanical, Refrigeration A, Steam & Hot Water, H & V A, Mechanical Systems Contractor, Electrical, Electrical Contractor, Class D Electrical Expires 2026 04 11, E200 General Electrical Qualifier, Mechanical A, General Contractor, Refrigeration, Mechanical Contractor, Trade, Commercial Mechanical Installations And Repair, General Class C, Commercial Building Contractor, Sheet Metal, One And Two Family Residential), which was Active when we last checked.

Colorado does not require contractors to take an exam or prove work experience, we advise homeowners to ask for multiple references when vetting a contractor to perform work on their homes.

Colorado does not require contractors to carry general liability insurance, but it is always a good idea to hire contractors who are covered by an active policy. Ask your contractor for copies of their policy before work starts.

A bond is not required in Colorado, consumers can file complaints with the Colorado Attorney General's Department of Consumer Protection.

Colorado does not run a financial or criminal background check on contractors prior to licensing so there is more responsibility on the consumer to make the right choice. Some consumers run their own background check on the Colorado Bureau of Investigation site before hiring.

The BuildZoom score is based on a number of factors including the contractor's license status, insurance status, verified work history, standing with local consumer interest groups, verified reviews from other BuildZoom users and self-reported feedback from the contractor.

When it comes to major construction work or even minor alterations to your home, hiring the wrong contractor could result in incomplete or defective work. You may even find yourself dealing with huge liability claims. BuildZoom does the homework for you and helps you hire the right contractor.

Before hiring a contractor in Colorado,be sure to get at least 3 detailed bids. Quality contractors will take the time to explain their budget proposal, and help guide you through the estimate process. Be wary of an abnormally low bid, they are not worth the risk. These underpriced projects often do not end well for the homeowner, choose a contractor you trust and can clearly communicate with. BuildZoom has made the bid collection process extremely simple (and free). Just click here to get started.