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Licensed contractors in Diamond Bar, CA
New this week
2 new licenses in Diamond Bar
Issued Oct 14 – Oct 20, 2026.
Browse by trade
- General Building B
- Electrical C-10
- Plumbing C-36
- Warm-Air Heating, Ventilating & Air-Conditioning (HVAC) C-20
- Painting & Decorating C-33
- General Engineering A
- Landscaping C-27
- Flooring & Floor Covering C-15
- Roofing C-39
- Low Voltage Systems C-7
- Ceramic & Mosaic Tile C-54
- Concrete C-8
- Cabinet, Millwork & Finish Carpentry C-6
- Swimming Pool C-53
- Glazing C-17
- Doors, Gates & Activating Devices D-28
- Fire Protection C-16
- Drywall C-9
- Building Moving & Demolition C-21
- Tree Service D-49
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Quick facts
How many licensed contractors are in Diamond Bar, CA?
311 contractors with a California CSLB license list a business address in Diamond Bar, CA. 295 of them have an active license in good standing (CSLB data as of 10/20/2026).
How many contractors in Diamond Bar, CA have a license problem right now?
16 are not in good standing right now, including 3 suspended for missing workers' comp. 21 active licenses expire within 90 days. Each listing below shows the status and a plain-English OK-to-hire verdict.
How do I check if a contractor is licensed?
Search the business name or license number on LicenseWatch CA to see license status, bond and workers' comp in one place, then confirm on the CSLB website before you sign a contract. In California, work over $1,000 in labor and materials requires a licensed contractor.
Featured spot availableLicensed contractors can claim this placement.
Claim your listing| Business | License | Status | Expires |
|---|---|---|---|
| 3 T Media Inc | 987903 | Active | 10/31/2027 |
| 5 Zero Inc | 1105104 | Active | 05/31/2027 |
| A And L Systems Solutions | 966840 | Active | 02/29/2028 |
| A E D Contractors | 441036 | Active | 03/31/2028 |
| A W Pirelli | 463755 | Active | 10/31/2026 |
| AC Heat Diamond Bar | 1145762 | Active | 10/31/2027 |
| Ace Iron Works | 539620 | Active | 08/31/2028 |
| Ace Plumbing Co | 785570 | Active | 10/31/2028 |
| Ace Rodil Heating And Air Conditioning | 631042 | Active | 10/31/2027 |
| Acemd Corporation | 1111963 | Active | 10/31/2027 |
| Adams Electric | 448001 | Active | 10/31/2027 |
| Advanced Tankless And Plumbing | 1121827 | Active | 06/30/2028 |
| Airpropower | 1150732 | Active | 02/29/2028 |
| All About T-Bar | 570421 | Active | 06/30/2027 |
| All Day Drains | 1088634 | Active | 03/31/2028 |
| Alliant Construction Services Inc | 1061441 | Active | 12/31/2027 |
| Allwayz Heating & Air Conditioning Inc | 1097372 | Active | 10/31/2028 |
| Alpha Construction Services Inc | 1015331 | Active | 06/30/2028 |
| American Resources Corporation | 895201 | Active | 04/30/2027 |
| Apex Construction Builder Inc | 1074739 | Active | 04/30/2027 |
| Apt Construction Inc | 1149695 | Active | 01/31/2028 |
| Aquarena Water Conditioning | 1160847 | Active | 09/30/2028 |
| Arkius Inc | 673454 | Active | 03/31/2027 |
| Arow Electric | 1129710 | Active | 11/30/2026 |
| Atlantic Air Conditioning Inc | 613226 | Active | 03/31/2027 |
| Avanti Membrane Technology Inc | 1091779 | Active | 05/31/2028 |
| Aveo Inc | 969881 | Active | 02/29/2028 |
| Barron Electric | 1104314 | Active | 05/31/2027 |
| Beshear Floor | 1100076 | Active | 12/31/2026 |
| Big Demolition And Construction | 1162961 | Active | 10/31/2028 |
| Big Elephant Construction Inc | 1031703 | Active | 10/31/2027 |
| Big Mango Renovation Inc | 1121648 | Active | 06/30/2028 |
| Blue Star Contractor | 1120031 | Active | 04/30/2028 |
| C - Thirty - Six Inc | 739644 | Active | 05/31/2028 |
| C S D M Inc DBA Cal Steam Company | 674646 | Active | 04/30/2027 |
| CA Sunshine Electrical | 1133255 | Active | 02/28/2027 |
| CFP Construction Inc | 700920 | Active | 01/31/2027 |
| CM Innovate Inc | 992367 | Active | 04/30/2028 |
| CT & T Concrete Paving Inc | 875627 | Active | 04/30/2028 |
| Cabinets 4 You LLC | 1112243 | Active | 05/31/2028 |
| Cany Fire Protection Inc | 1142986 | Active | 09/30/2027 |
| Carve Modular Corporation | 1154699 | Active | 05/31/2028 |
| Castaneda Construction | 932830 | Active | 05/31/2027 |
| Centaline Construction Inc | 1145427 | Active | 10/31/2027 |
| Chung Chieh Wu | 1105504 | Active | 06/30/2027 |
| Chyr-Shin Paul Tsao | 670052 | Active | 04/30/2027 |
| Ciel Air Conditioning And Electric | 1039457 | Active | 05/31/2028 |
| Climate Specialists | 1003654 | Active | 05/31/2027 |
| Colony On Green | 951899 | Active | 09/30/2028 |
| Consma Inc | 951561 | Active | 04/30/2028 |
| D A S Builder Inc | 1044031 | Active | 07/31/2027 |
| D C M Remodel Specialties DBA Douglas Charles Malo Construction | 972557 | Active | 05/31/2028 |
| D D Y Improvement Corp | 925637 | Active | 12/31/2026 |
| D R O - West Construction | 754069 | Active | 09/30/2028 |
| DK Air & Refrigeration | 1123000 | Active | 06/30/2028 |
| DZ Prime Construction | 1129072 | Active | 11/30/2026 |
| Daniel C Pun | 866867 | Active | 11/30/2027 |
| Dannys Installation Of Appliances | 984698 | Active | 06/30/2027 |
| Datang Building Service Inc | 1103658 | Active | 04/30/2027 |
| David Liang Hua Peh | 882040 | Active | 08/31/2028 |
| Dayone Construction | 1157614 | Active | 07/31/2028 |
| Dcloud Homes | 1106436 | Active | 08/31/2027 |
| Derek Sim | 977202 | Active | 09/30/2028 |
| Devin Electric | 878672 | Active | 06/30/2028 |
| Diamond Elevator Services | 1021983 | Active | 12/31/2026 |
| Dolores K Martin | 430320 | Active | 10/31/2026 |
| Donglianglu | 1145119 | Active | 10/31/2027 |
| Dongqiang Lu | 1139854 | Active | 07/31/2027 |
| Dream Space Construction | 1071725 | Active | 12/31/2026 |
| Dreamer Construction And Development | 1125664 | Active | 08/31/2028 |
| Duke Builders Corp | 635180 | Active | 01/31/2028 |
| Dux Technology Consulting Inc | 1050592 | Active | 02/28/2027 |
| Dyconn Inc | 1093822 | Active | 07/31/2028 |
| Dynamic Solar | 1006299 | Active | 08/31/2027 |
| Echo Development Inc | 993395 | Active | 06/30/2028 |
| Ecp Construction | 1150062 | Active | 02/29/2028 |
| Edesh Enterprise Inc DBA Edesh Construction | 1020843 | Active | 11/30/2026 |
| Edward Caruso Electric | 529763 | Active | 05/31/2028 |
| Electech | 982409 | Active | 04/30/2027 |
| Elite Pipe P | 1144688 | Active | 10/31/2027 |
| Evercraft Construction Inc | 1122597 | Active | 06/30/2028 |
| Expedite Plumbing | 939646 | Active | 10/31/2027 |
| F S Construction | 928966 | Active | 01/31/2028 |
| Falkon Construction Inc | 911791 | Active | 03/31/2028 |
| Fangzhou Chen Construction | 1040290 | Active | 06/30/2028 |
| Fill Good Landscaping | 1053396 | Active | 05/31/2027 |
| Forest & Sun Arborist Designers Landscapers | 893193 | Active | 03/31/2027 |
| Four Seasons Air Conditioning And Heating | 966880 | Active | 10/31/2027 |
| Freddie Vega | 1138185 | Active | 05/31/2027 |
| Fueltec Inc | 1011678 | Active | 03/31/2028 |
| G A N Signs & Graphic Inc | 1008442 | Active | 10/31/2027 |
| G C Plumbing | 681446 | Active | 12/31/2027 |
| G L Construction Group Inc | 994049 | Active | 06/30/2028 |
| G Miller Development Co | 325200 | Active | 12/31/2027 |
| Galvan Plumbing | 1065435 | Active | 04/30/2028 |
| Gary & Son Construction | 1138649 | Active | 06/30/2027 |
| Gary's AC Services | 921063 | Active | 08/31/2028 |
| Giant Palms Construction Inc | 1072035 | Active | 12/31/2026 |
| Gonzalez Electric | 962683 | Active | 06/30/2027 |
| Grand Space | 1075915 | Active | 05/31/2027 |
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