| 3-d Plumbing | Glen William Dart | — | (707) 628 9947 | Other | Rio Vista · Solano County | — | — |
| 425 General Engineering INC | Alonso Ojeda | info@general-engineering.com | (510) 342 8013 | Other | Vacaville · Solano County | — | — |
| 4L Artistic Tile | Rudin Luis Roche | — | (415) 596 7043 | Other | Vallejo · Solano County | — | — |
| A - 1 Cabinets | A - 1 Cabinets | — | (707) 678 1551 | Other | Dixon · Solano County | — | — |
| A B C Plumbing | A B C Plumbing | john@abcplumbing.com | (707) 452 1364 | Other | Vacaville · Solano County | — | — |
| A B Fencing | A B Fencing | — | (707) 864 8629 | Other | Fairfield · Solano County | — | — |
| A G A Tile Stone | A G A Tile Stone | — | (415) 827 6775 | Other | Vallejo · Solano County | — | — |
| A G Plastering | A G Plastering | — | (925) 642 0376 | Other | Fairfield · Solano County | — | — |
| A M Access Control INC | Martin Hernandez | — | (800) 421 1924 | Other | Fairfield · Solano County | — | — |
| A R M S Rooter & Plumbing Services | Angel Ramos Martinez | — | (707) 438 2767 | Other | Suisun City · Solano County | — | — |
| A Robledo Construction General Engineering INC | Robledo Alvaro | — | (707) 492 9508 | Other | Fairfield · Solano County | — | — |
| A S Fire Protection | A S Fire Protection | micah@micahrich.com | (650) 430 1527 | Other | Benicia · Solano County | — | — |
| A T O M Plumbing | A T O M Plumbing | — | (510) 565 9550 | Other | Vallejo · Solano County | — | — |
| Aaa Construction | Alvarado Arzate Alejandro | yuriy@aaaconstruction.com | (707) 580 7795 | Other | Suisun City · Solano County | — | — |
| Aaa Earthwork Ag & Habitat | Austin Clark Jr Wedemeyer | — | (707) 246 7796 | Other | Fairfield · Solano County | — | — |
| Ab Garage Doors INC | Manpreet Singh Bhangu | — | (510) 640 6090 | Other | Dixon · Solano County | — | — |
| Ab Plumbing | Aaron Bryce Blair | — | (916) 410 9109 | Other | Fairfield · Solano County | — | — |
| Abbott Concrete LLC | Jason David Abbott | — | (707) 758 6141 | Other | Benicia · Solano County | — | — |
| Able Asphalt | Able Asphalt | — | (707) 340 6065 | Other | Vacaville · Solano County | — | — |
| Above And Beyond Plumbing Services | James Bernard Brandon | — | (707) 363 5013 | Other | Fairfield · Solano County | — | — |
| Accessibility Service Company | Brian Shane Hofacre | — | (707) 246 4214 | Other | Fairfield · Solano County | — | — |
| Accurate Elevators LLC | David Patrick Ferguson | — | (714) 791 9884 | Other | Fairfield · Solano County | — | — |
| Act Now Fire Inspections | Eric Albert Talistu | — | (855) 228 6699 | Other | Fairfield · Solano County | — | — |
| Action Asphalt | Shawn Christopher Peterson | info@actionasphalt.com | (707) 529 7478 | Other | Vacaville · Solano County | — | — |
| Adams Engineering | Adams Engineering | — | (707) 678 0514 | Other | Dixon · Solano County | — | — |
| Adams Plumbing | Patrick Ryan Adams | — | (707) 880 8849 | Other | Vacaville · Solano County | — | — |
| Adolfo's Plumbing & Rooter LLC | Adolfo Ventura | — | (415) 624 4416 | Other | Fairfield · Solano County | — | — |
| Advance Asphalt INC | Brittany Buffy Wasso | — | (707) 543 2901 | Other | Vacaville · Solano County | — | — |
| Advantage Paving & Grading | Amber Rose Peterson | — | (707) 628 9667 | Other | Dixon · Solano County | — | — |
| Aet Consulting INC DBA Cozy Plumbing Services | Gary Jason Grant | — | (707) 474 5097 | Other | Vacaville · Solano County | — | — |
| Ag Plumbing Co | Adolfo Alejandro Garcia Garcia | — | (707) 564 7209 | Other | Vacaville · Solano County | — | — |
| Aguirre Reinforcing Steel LLC | Pablo Omar Aguirre | — | (707) 515 5587 | Other | Vallejo · Solano County | — | — |
| Ahl American Automatic Door Service | James Anthony Ahl | — | (707) 447 9518 | Other | Vacaville · Solano County | — | — |
| Air Exchange INC | Chris Koss | — | (707) 864 2700 | Other | Fairfield · Solano County | — | — |
| Alejandro's Plumbing | Alejandro's Plumbing | — | (707) 689 7930 | Other | Fairfield · Solano County | — | — |
| Alfred Conhagen INC Of California | Michael Phillip Petrellese | — | (707) 746 4848 | Other | Benicia · Solano County | — | — |
| All About Asphalt | All About Asphalt | interested@domainmarket.com | (916) 899 0229 | Other | Dixon · Solano County | — | — |
| All American Concrete | All American Concrete | — | (707) 974 0127 | Other | Fairfield · Solano County | — | — |
| All American Elevator Company INC | Nicholas Leonard Piano | — | (877) 653 5123 | Other | Benicia · Solano County | — | — |
| All American Paving | All American Paving | — | (844) 572 8348 | Other | Vacaville · Solano County | — | — |