| 3 - D Enterprises Incorporated | C10 + A, B, C8 +3 | 1991 | Active |
| 555 Construction | C10 + A, B, C7 | 2019 | Active |
| A - Lectric Inc | C10 | 2023 | Active |
| A E Audio | C10 | 2005 | Active |
| A Frame Electric Inc | C10 | 2011 | Active |
| A G A Electric & Consulting Services Inc | C10 | 2008 | Renew by Nov 30, 2026 |
| A M E West | C10 + A, B, C27 | 2007 | Active |
| A M Electric Services Inc | C10 | 2022 | Active |
| A P L Electrical Inc | C10 + B | 2006 | Active |
| A Plus Lighting | C10 + B, C27 | 2014 | Active |
| A-Intelec | C10 | 2026 | Active |
| Aaa Electrical Solutions SD LLC | C10 | 2026 | Active |
| AC / DC Electric S D Inc | C10 | 2008 | Renew by Dec 31, 2026 |
| Accubuild Construction Inc | C10 + B | 1995 | Active |
| Adaly Electrical & Energy Solutions Inc | C10 + C36 | 2022 | Active |
| Adar Electric Corporation | C10 | 2011 | Active |
| Advantage Security And Multimedia Inc | C10 | 2006 | Active |
| Ahrens Mechanical | C10 + A, B, C4 +7 | 2011 | Active |
| Airmaxx Inc | C10 + C20 | 2008 | Active |
| Alarms Unlimited Incorporated | C10 + C7, D28 | 1981 | Active |
| Alfaro Electrical Services | C10 | 2024 | Active |
| All City Electric Inc | C10 + B | 2013 | Active |
| All Phases And Trades Construction Corp | C10 + B | 2007 | Active |
| Alliance Electrical Systems Inc | C10 | 2017 | Active |
| Allstate Electric | C10 + B | 1990 | Active |
| Alltech Solar Inc | C10 + B, C20, C46 | 1995 | Active |
| Always On Electric Inc | C10 | 2022 | Active |
| Always Quality Electrical Inc | C10 | 1983 | Active |
| American Construction | C10 + B, C20, C36 | 2017 | Active |
| American Global Technologies Inc | C10 + B | 2023 | Active |
| Anchor Point Construction Inc | C10 + B, C36 | 2007 | Active |
| Andre Electric, Inc | C10 + B | 2024 | Active |
| Andrews Brothers Electric Inc | C10 | 2010 | Active |
| Anton Electric Inc | C10 | 1996 | Active |
| Apex Lighting And Electric Inc | C10 | 2001 | Renew by Dec 31, 2026 |
| Apex Works Inc | C10 + A, B, C36 | 2025 | Active |
| Aq Electric Inc | C10 | 2025 | Active |
| Arc Power Solutions Inc | C10 | 2018 | Active |
| Arctek Electric Inc | C10 | 2026 | Active |
| Argo Performance LTD | C10 + C7, C20, D62 | 2015 | Active |
| Atel Technologies Inc | C10 | 2024 | Active |
| Attic Projects LLC | C10 + B, C2 | 2018 | Active |
| Audio Impact Inc | C10 + C7 | 2005 | Active |
| Aura Design Build LLC | C10 + A, B | 2024 | Active |
| Axion Construction Inc | C10 + A, B, C36 | 2016 | Renew by Nov 30, 2026 |
| B V I Solar | C10 + B, C39, C46 | 2017 | Active |
| Balcazar Electric Inc | C10 | 2021 | Renew by Nov 30, 2026 |
| Bariom Inc | C10 | 2023 | Active |
| Bashaw Electric Inc | C10 | 2017 | Active |
| BDR Electric | C10 | 2023 | Active |
| Bee Connected Electric | C10 | 2022 | Active |
| Ben Moore Electric Inc | C10 | 2018 | Active |
| Bergelectric-Helix A Joint Venture | C10 | 2015 | Active |
| Biosources Inc | C10 + B, C20 | 1997 | Active |
| Blue Mountain Heating And Cooling | C10 + C20 | 2020 | Active |
| Blue Pacific Engineering Construction Inc | C10 + A, B, C8 +3 | 2003 | Active |
| Blue Planet Energy Solutions | C10 | 2013 | Active |
| Blue Wave Electric Inc | C10 | 2021 | Active |
| Blues Electric | C10 + C20 | 2020 | Renew by Dec 31, 2026 |
| BP Solar Electric | C10 | 2018 | Active |
| Brenneis Electric | C10 | 1984 | Active |
| Bri Electric Group Inc | C10 + A, B, C27 | 1990 | Active |
| Briccola Electrical LLC | C10 | 2014 | Active |
| Bright Electric & Solar | C10 | 2022 | Active |
| Bright Power Contractors Inc | C10 | 2023 | Active |
| Bright Power Electric Inc | C10 | 2025 | Active |
| Brightside Inc | C10 + B, C36 | 2012 | Renew by Dec 31, 2026 |
| Brightway Electric | C10 | 2024 | Active |
| Brown R J General & Electrical Contracting Inc | C10 + B | 1999 | Active |
| Build Brothers Inc | C10 + B, C20, C39 | 2014 | Active |
| Burtek Energy LLC | C10 + A, B, C20 +1 | 2016 | Active |
| C West Electric Inc | C10 | 2013 | Active |
| Cabrillo Electric Inc | C10 | 1991 | Active |
| Cal Pacific Industries Inc | C10 | 2019 | Active |
| Calafata Construction And Electric Inc | C10 + B | 2004 | Active |
| Cali Coast Contractors Inc | C10 + A, B | 2025 | Active |
| Caliber Contracting San Diego | C10 + B | 2024 | Active |
| California Commercial Security | C10 + C7, C28 | 1997 | Active |
| California Security & Video Systems | C10 + C7 | 1982 | Active |
| California Solar Integrators Inc | C10 + B, C46 | 2015 | Active |
| Calispark Electric | C10 | 2024 | Active |
| Candee Electric | C10 | 2023 | Active |
| Carter Ben Electric Inc | C10 | 2009 | Active |
| Carter Electric Inc | C10 | 1987 | Active |
| Castle Electric Company Inc | C10 | 1995 | Active |
| Castle Electric SD Inc | C10 | 2015 | Active |
| Cec Electric Inc | C10 | 2020 | Active |
| Cet Electric | C10 | 2015 | Active |
| Chris O'Malley BLDG | C10 + B | 2007 | Active |
| City Electric Works Incorporated | C10 | 1979 | Active |
| Clear Blue Energy Corp | C10 + B | 2010 | Active |
| CLS Security Electronics | C10 + C7 | 1993 | Active |
| CM Solar Electric | C10 | 2013 | Active |
| Coffman Specialties Inc | C10 + A | 1991 | Active |
| Collier Electric Inc | C10 | 1983 | Active |
| Commercial Improvement Services Inc | C10 | 1994 | Active |
| Commercial Plumbing & Building Inc | C10 + B, C36 | 2005 | Active |
| Communication Wiring Specialists Inc | C10 + C7, C20, C36 | 1991 | Active |
| Community Construction Concepts Inc | C10 + B | 2021 | Active |
| Connor Energy Services | C10 + C46 | 2024 | Active |