| A & B Mechanical INC | Deborah Gail Byrkit | — | (510) 264 5800 | HVAC | Hayward · Alameda County | — | — |
| A & B Plumbing & Backflow | Michael Anthony Branco | — | (510) 471 4282 | Other | Hayward · Alameda County | — | — |
| A & E Emaar Company | Usama Mohamed El-Saied | — | (510) 253 5337 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| A & F Garage Doors And Construction | Fernando Duran Martinez | — | (510) 604 6040 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| A & G Construction | Zhao Gary | — | (415) 407 4279 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| A & J Painting INC | Alan Kennith Joyce | — | (510) 292 3668 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| A & K Underground | A & K Underground | — | (650) 222 4058 | Other | Newark · Alameda County | — | — |
| A & M Lath & Plastering INC | Moises Meza Gastelum | — | (510) 332 7629 | Other | Hayward · Alameda County | — | — |
| A & S Garage Door Services | Christopher Lawrence Wolosz | — | (510) 489 3189 | Other | Hayward · Alameda County | — | — |
| A & V Drywall | A & V Drywall | — | (510) 815 3288 | Other | Alameda · Alameda County | — | — |
| A + Landscaping And Hauling Service | Hernandez David | — | (510) 604 6580 | Windows, patio, painters | Hayward · Alameda County | — | — |
| A + Wood Flooring Solution | A + Wood Flooring Solution | — | (510) 759 5466 | Other | San Leandro · Alameda County | — | — |
| A - 1 Property Construction | David Michael Perman | — | (925) 686 4663 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| A - Brother Construction | Asikia Pati | — | (650) 518 0617 | GC, remodel, ADU | Newark · Alameda County | — | — |
| A - One Construction | Andrew Jacob Triphon | — | (510) 347 5400 | Other roofers | Fremont · Alameda County | — | — |
| A - Tron Electric INC | Abner Abisai Alvarez Castillo | — | (415) 847 0314 | Electricians | Dublin · Alameda County | — | — |
| A / Global General Contractor | A / Global General Contractor | — | (408) 991 3363 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| A 1 General Building | A 1 General Building | — | (510) 712 5854 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| A A A Tree Service INC | Antonio Hurtado | — | (510) 538 8761 | Tree | Hayward · Alameda County | — | — |
| A A E Group Construction Corp | Ahmad Ali Eslami | — | (510) 774 8387 | Electricians | Berkeley · Alameda County | — | — |
| A A Electric | Ashween Ashnil Prasad | — | (650) 834 2603 | Electricians | Hayward · Alameda County | — | — |
| A A Johnson & Son INC | Lawrence Neldam Twomey | — | (510) 658 9796 | Other | Oakland · Alameda County | — | — |
| A A Office Equipment Co INC | John Charles Procita | — | (510) 782 6110 | Other | Hayward · Alameda County | — | — |
| A B Alpha Roofing | Bello Miranda Alejandro | — | (510) 967 2643 | Other roofers | Oakland · Alameda County | — | — |
| A B C Construction | Luis Eduardo Alves | — | (510) 895 6200 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| A B C Construction | Xuan Van Le | — | (510) 499 2660 | Electricians | San Lorenzo · Alameda County | — | — |
| A B C Flooring | A B C Flooring | — | (650) 518 1674 | Other | Oakland · Alameda County | — | — |
| A B C Painting Co | Song Inhwan | — | (510) 278 6356 | Windows, patio, painters | San Lorenzo · Alameda County | — | — |
| A B Plumbing | A B Plumbing | — | (415) 333 5566 | Other | Oakland · Alameda County | — | — |
| A B T Electric | Mease Buthan | — | (510) 489 3477 | Electricians | Hayward · Alameda County | — | — |
| A Better Roofing Company | Brett James Moran | — | (925) 370 1158 | Other roofers | Livermore · Alameda County | — | — |
| A Better Rooter Plumbing & Engineering INC | Jacques Michel Etienne | — | (510) 527 1219 | Other | Berkeley · Alameda County | — | — |
| A C Armstrong Construction | Arnold Calvin Armstrong | — | (510) 384 1062 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| A C C Electric Co | Albert Sung Chiu | — | (510) 748 1298 | Electricians | Alameda · Alameda County | — | — |
| A C Construction | Cimpoaie Aurel | — | (510) 303 4691 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| A C E Electric Co | Shaun Arthur Allen | — | (925) 606 8610 | Electricians | Livermore · Alameda County | — | — |
| A C Garage Doors | A C Garage Doors | — | (408) 857 8355 | Other | Newark · Alameda County | — | — |
| A C Logix Incorporated | Christopher Andre Mosser | — | (925) 846 9991 | HVAC | Pleasanton · Alameda County | — | — |
| A C P Electric | Anthony Carlo Pagano | — | (510) 701 6458 | Electricians | San Leandro · Alameda County | — | — |
| A C T Glass | A C T Glass | — | (510) 487 6731 | Windows, patio, painters | Hayward · Alameda County | — | — |