Founded in 1902 by a coalition of entrepreneurs who “guaranteed” to light the 1904 World’s Fair, Guarantee Electrical Company has grown into one of the largest and most respected national electrical contracting firms. In 2023 Guarantee became a 100% ESOP owned company. Our team of more than 1000 engineers, project managers, IBEW craft workers and office staff provides a complete spectrum of electrical services that exceed our customers’ requirements and expectations, and earn repeat opportunities to serve.

2021 saw the expansion of Guarantee into new geographic and vertical markets. In June, Guarantee acquired Berwick Electric, a Colorado Springs-based contractor specializing in federal, industrial and commercial electrical contracting. In December, Guarantee grew it's midwestern presence by acquiring fellow St. Louis-based contractor, Aschinger Electric. From engineering complex design-build projects to providing niche specialty services like electric vehicle charging and solar, our combined resources allows us to accommodate every type of buyer with a one-stop-shop, turnkey solution.   

With offices in four states (Missouri, Illinois, Colorado and California), Guarantee delivers services throughout the United States. Our affiliation with the Federated Electrical Contractors (FEC) further expands our reach, with partner firms in 60 cities around the globe.

Engineering News-Record consistently ranks Guarantee among the top electrical, and specialty contractors in the United States. We serve our customers nationwide with the best in electrical engineering design, design-assist, value engineering, procurement, service and preventive maintenance.

Markets; healthcare, medical equipment install, industrial, commercial, data center, automotive, power utility, manufacturing, tilt up, lighting retrofit, solar, electric vehicle, EV charging, renewable energy, assisted living, apartments, high rise residential, systems, fire alarm, structured cabling, audio visual, nurse call, security systems, temperature control, HVAC, automation, process controls, civil, ductbanks, engineering, CAD, BIM, 3D Modeling, Design Build, cost analysis, estimating, quick response, 24 hour service, emergency, high voltage, line, prefabrication, modularization, maintenance, infra red scope, metering and monitoring