| A - Team Tree Service INC | Adam Richard Rohrbough | — | (530) 306 9613 | Tree | Pollock Pines · El Dorado County | — | — |
| A - Tech Electric | Marco Antonio Pineda | — | (951) 300 6973 | Electricians | Moreno Valley · Riverside County | — | — |
| A - Tech Electric INC | Henry Lin | — | (415) 308 8649 | Electricians | San Francisco · San Francisco County | — | — |
| A - Tech Plumbing & Fire Protection | Leung Powing | — | (510) 918 3330 | Other | Cupertino · Santa Clara County | — | — |
| A - Tek Mechanical INC | Curly Khamla Phom | — | (619) 944 8757 | HVAC | Murrieta · Riverside County | — | — |
| A - Tile Co | Donald William Abreu | — | (408) 396 6331 | Other | Santa Clara · Santa Clara County | — | — |
| A - Total Fire Protection Company INC | Monte Lee Osborn | accounting@atotalfireprotection.com | (530) 672 8495 | GC, remodel, ADU | Cameron Park · El Dorado County | — | — |
| A - Town Glass & Window | Carreon Manuel | — | (805) 674 4309 | GC, remodel, ADU | Atascadero · San Luis Obispo County | — | — |
| A - Town Media | A - Town Media | — | (805) 423 1523 | Other | Atascadero · San Luis Obispo County | — | — |
| A - Tron Electric INC | Abner Abisai Alvarez Castillo | — | (415) 847 0314 | Electricians | Dublin · Alameda County | — | — |
| A - Twister | A - Twister | — | (818) 616 4204 | Other | Van Nuys · Los Angeles County | — | — |
| A - Z Building Services | Blake Raymond Spon | — | (530) 990 8831 | HVAC | Bangor · Butte County | — | — |
| A - Z Capital Construction | Getman Yuriy | — | (916) 997 4646 | GC, remodel, ADU | Sacramento · Sacramento County | — | — |
| A - Z Pro Landscaping | A - Z Pro Landscaping | — | (510) 461 4592 | Windows, patio, painters | American Canyon · Napa County | — | — |
| A - Z Tile | A - Z Tile | — | (408) 828 1895 | Other | San Jose · Santa Clara County | — | — |
| A - Zap Electric | Shawn Michael Hannegan | a_zapelectric@hotmail.com | (805) 520 0774 | Electricians | Simi Valley · Ventura County | — | — |
| A - Zap Electric | Steven John Fogal | a_zapelectric@hotmail.com | (209) 274 4966 | Electricians | Ione · Amador County | — | — |
| A -1 Construction | Scott Patrick Eakins | — | (559) 905 4001 | GC, remodel, ADU | Clovis · Fresno County | — | — |
| A / B Plastering | A / B Plastering | — | (951) 545 1523 | Other | Moreno Valley · Riverside County | — | — |
| A / C Control INC | Babak Allan Firoozi | — | (310) 909 4814 | HVAC | Los Angeles · Los Angeles County | — | — |
| A / C Electric | Adrien Benny Cedillo | — | (408) 887 2600 | Electricians | Santa Clara · Santa Clara County | — | — |
| A / C Mechanical Sol INC | Bozickovic Mladen | — | (858) 733 1534 | HVAC | San Diego · San Diego County | — | — |
| A / C Solutions INC | Casey Al Hudson | — | (951) 448 3432 | HVAC | Murrieta · Riverside County | — | — |
| A / G Electric | Aguilar Gilbert | — | (408) 422 6266 | Electricians | Galt · Sacramento County | — | — |
| A / G General Contracting And Painting INC | Anthony Carl| Gonzales Tony Carl Gonzales | — | (619) 585 1515 | GC, remodel, ADU | Pine Valley · San Diego County | — | — |
| A / Global General Contractor | A / Global General Contractor | — | (408) 991 3363 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| A 1 - Stop Garage Door Company | Karl Lee Meidell | — | (661) 947 8464 | Other | Palmdale · Los Angeles County | — | — |
| A 1 - Stump Removal | A 1 - Stump Removal | — | (408) 439 6975 | Tree | San Jose · Santa Clara County | — | — |
| A 1 A Engineering & Construction INC | Song Hong | — | (213) 248 1033 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| A 1 Air Conditioning & Heating | Marie Annette Memoli | — | (661) 822 1173 | HVAC | Tehachapi · Kern County | — | — |
| A 1 Budget Plumbing | A 1 Budget Plumbing | — | (650) 291 3743 | Other | Burlingame · San Mateo County | — | — |
| A 1 Carpet Market | Adel Chafic Tayara | — | (310) 327 0514 | Other | Torrance · Los Angeles County | — | — |
| A 1 Construction & Designs INC | Irit Friedman | — | (310) 350 3583 | GC, remodel, ADU | Los Angeles · Los Angeles County | — | — |
| A 1 Construction Co | Kwang Hyun Paek | — | (714) 797 9000 | GC, remodel, ADU | Phelan · San Bernardino County | — | — |
| A 1 Construction INC | Krikor Abajian | — | (818) 266 1444 | GC, remodel, ADU | Azusa · Los Angeles County | — | — |
| A 1 Copper Repipe Specialist | A 1 Copper Repipe Specialist | — | (562) 423 0777 | Other | Long Beach · Los Angeles County | — | — |
| A 1 Demolition | Samuel Humberto Bonilla | — | (310) 529 5466 | Other | Compton · Los Angeles County | — | — |
| A 1 Electrical | Karen Kevin Petrosyan | — | (916) 482 3400 | Electricians | Sacramento · Sacramento County | — | — |
| A 1 Fabrication & Welding INC | William Demitrios Perparos | — | (916) 349 8700 | Other | Sacramento · Sacramento County | — | — |
| A 1 Fence Company | Matthew Joseph Tuckett | — | (650) 873 7272 | Windows, patio, painters | South San Francisco · San Mateo County | — | — |