| Konikow Electric Inc | C10 | 1987 | Active |
| L A One Corp | C10 + B | 2018 | Renew by Nov 30, 2026 |
| Lamb Energy Inc | C10 | 1996 | Active |
| Lavang Controls Corp | C10 + C20 | 2005 | Active |
| Lce Telecom Inc | C10 + C7, C20 | 2017 | Active |
| Leivas Lighting | C10 | 2010 | Active |
| Light Energy Inc | C10 + B, C39 | 2020 | Active |
| Lightupenergy LLC | C10 | 2025 | Active |
| Luxor Energy Inc | C10 | 2023 | Active |
| M & S Equipment Inc | C10 + A, C34, C36 | 1989 | Active |
| Maher Communications | C10 + C7 | 2019 | Active |
| Marquez Electrical Services Inc | C10 | 2021 | Active |
| Masters Electric | C10 + B, C7, C46 | 1999 | Active |
| Mata Inc | C10 | 2025 | Active |
| MC Donald Electric Inc | C10 | 2010 | Active |
| Meeks Electric Inc | C10 | 2018 | Active |
| Micom Inc | C10 + C7, D49 | 2002 | Active |
| N Line Electric Inc | C10 | 2021 | Active |
| Neal D J Construction Inc | C10 + B | 1995 | Active |
| Netgain Networks Inc | C10 + B, C7 | 2008 | Active |
| New Alliance Security Inc | C10 | 2023 | Active |
| Nick's Electrical Contractors Inc | C10 + B | 2023 | Active |
| Norris Tower Incorporated | C10 | 2000 | Active |
| Optimum Solar Power Inc | C10 + A, C46 | 2017 | Active |
| P T M General Engineering Services Inc | C10 + A, B, C7 +9 | 2007 | Active |
| Pacific Coast Electric | C10 | 2026 | Active |
| Pacific Pro Solar Group Inc | C10 + C46 | 2010 | Active |
| Parking Electrical | C10 | 2016 | Active |
| Peak360 Electrical Security Solutions | C10 | 2025 | Active |
| Portugal Electric | C10 | 2024 | Active |
| Positive Electric LLC | C10 | 2022 | Active |
| Power Off Electric Inc | C10 | 2026 | Active |
| Powertown Solar Electric Inc | C10 | 2011 | Active |
| Premier Contracting Services Inc | C10 | 2025 | Active |
| Prestige Electric | C10 | 2026 | Active |
| Pro Elite Security Systems LLC | C10 | 2009 | Active |
| Pro Status Electric | C10 | 2022 | Active |
| Pulse Industrial Electric Inc | C10 | 2020 | Active |
| Pump Check Inc | C10 + D21 | 2001 | Active |
| Quintero's Electric Inc | C10 | 1992 | Active |
| R C Technology Electric Inc | C10 | 2017 | Active |
| R D H Electric | C10 | 2021 | Active |
| R I S Electrical Contractors Inc | C10 + B, C31 | 1995 | Active |
| R S D Alarms | C10 | 2012 | Active |
| Raincross Electric Inc | C10 | 2025 | Active |
| Rehab Building Co Inc | C10 + B | 2014 | Active |
| Rocket Enterprises | C10 + B | 2014 | Active |
| S&W Electric Company LLC | C10 | 2022 | Active |
| S-Line Contractors | C10 + B, C8, C34 | 2019 | Active |
| Safeway Electric | C10 + B, C7, C46 | 1980 | Active |
| Semna | C10 + A | 2021 | Active |
| Seven Star Electric | C10 | 2019 | Active |
| Sharp Electrical Services | C10 + B, C39, C47 | 2019 | Active |
| Sherwood Construction & Electric Inc | C10 + B | 1984 | Active |
| Sigma One Construction Inc | C10 + A | 2024 | Active |
| Skanska - Traylor - Shea A Joint Venture | C10 + A, B, HAZ | 2013 | Active |
| Skanska USA Civil West California District Inc | C10 + A, C34, HAZ | 1953 | Active |
| Skyline Construction | C10 + B, C20 | 2015 | Active |
| Smart Power Electric Inc | C10 | 2020 | Active |
| SMH Electrical Construction | C10 | 2024 | Active |
| Socal Competitive Electric Inc | C10 + D63 | 2011 | Active |
| Solarcon Inc | C10 + B, C17, C20 +2 | 2015 | Active |
| Solaria Solar LLC | C10 | 2026 | Active |
| Solarmax Contracting | C10 | 2015 | Active |
| Solarmax Renewable Energy Provider Inc | C10 + C46 | 2012 | Active |
| Solid Ground Electrical LLC | C10 | 2022 | Active |
| Sonray's LLC | C10 | 2026 | Active |
| Sprint Electric Inc | C10 | 1998 | Active |
| Stay Grounded Electric Inc | C10 | 2016 | Active |
| Stellar Energy LLC | C10 + B | 2024 | Active |
| Stellar Technology & Automation Corp | C10 | 2026 | Active |
| Stronghold Power Systems Inc | C10 + A, B | 2019 | Active |
| Superior Electrical Technologies PC | C10 | 2015 | Active |
| Supreme Electric LLC | C10 | 2021 | Active |
| Tec-Line Electrical Contractors Inc | C10 | 2025 | Active |
| Tess Electric Inc | C10 | 2019 | Active |
| Tri County Consultants | C10 + C7 | 2012 | Renew by Nov 30, 2026 |
| Trout Electric | C10 | 2009 | Active |
| Unity Electric And Solar LLC | C10 | 2024 | Active |
| Utility Inc | C10 + B | 2022 | Active |
| Vaughn Dustie Construction | C10 + B | 2018 | Active |
| Vector Media Solutions Inc | C10 | 2018 | Active |
| Vogue Electrical Inc | C10 + B | 2022 | Active |
| W A M Construction Inc | C10 + B | 2020 | Active |
| Walther Electrical Service Inc | C10 | 1993 | Active |
| Weber Water Resources Ca LLC | C10 + A, C57, D21 | 2012 | Active |
| Weissker Herman Inc | C10 + A | 1959 | Active |
| West Coast Power Solution | C10 + B | 2023 | Active |
| Westcoast Solar Professional | C10 + B, C46 | 2018 | Active |
| Western Pacific Integrated Systems | C10 + C16 | 2012 | Active |
| Will Power Electric | C10 | 2025 | Active |
| Xfinity Electric Inc | C10 + B | 2018 | Active |
| Y K Electric Inc | C10 | 2023 | Active |
| Yireh Electric Inc | C10 | 2019 | Renew by Nov 30, 2026 |
| Yunex LLC | C10 + A | 2021 | Active |
| Zobel Electric LLC | C10 | 2018 | Active |