| A3 Pipeline | Alfredo Gonzalez | — | (415) 300 0364 | Other | San Francisco · San Francisco County | — | — |
| A5 Builders | Alfredo Gonzalez | — | (510) 374 9845 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Aaa Electric Co | Arafat K Al-Ali | — | (415) 570 1014 | Electricians | San Francisco · San Francisco County | — | — |
| Aak Builders Corp | Daniel Wei An Kwan | — | (415) 336 2793 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Aaron Gordon Construction INC | Aaron Lee Gordon | — | (415) 682 4242 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Abadub Construction INC | Alexandr Polcanov | sales@abadubconstruction.com | (628) 222-4891 | Electricians | San Francisco · San Francisco County | — | — |
| Abbeyside Construction INC | Mike Coleman | ametcheverria@abbeysideconstruction.com | (310) 469 3654 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Abbley General Contracting | Victor Kane Abbley | — | (805) 431 7311 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Abco Mechanical Contractors INC | Nicholas Shawn Lanthier | — | (415) 648 7135 | HVAC | San Francisco · San Francisco County | — | — |
| Abel Glass Co. | Abel Glass Co. | — | (415) 401-9725 | Windows, patio, painters | San Francisco · San Francisco County | — | — |
| Aber Team INC | Stephen Aber | — | (650) 207 5723 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Able Handyman & Contractor | Sergio Floriano Haesbaert | — | (415) 756 7961 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Above Engineering Corporation | Cherubim Jake Speaks | sales@above-engineering.com | (628) 888 5400 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Abr Pro Painting | Abr Pro Painting | — | (415) 525 0944 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| AC Heating And Cooling Service Inc. | AC Heating And Cooling Service Inc. | — | (415) 333-9903 | HVAC | San Francisco · San Francisco County | — | — |
| AC Power Electrical Contractor | Abraham Castaneda | — | (707) 213 0397 | Electricians | San Francisco · San Francisco County | — | — |
| Acacia Glass Corp | Thomas David Kenihan | — | (415) 661 4591 | Windows, patio, painters | San Francisco · San Francisco County | — | — |
| Accend Electric | Paula Phouilang Wong | — | (408) 784 2345 | Electricians | San Francisco · San Francisco County | — | — |
| Access Scaffolding Co | Igor Vassiliev | — | (510) 230 5040 | Other | San Francisco · San Francisco County | — | — |
| Accm Construction & Development | Wing Tung Lau | — | (415) 309 3623 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Accu Painting Company INC | Shannon Marie Peich | — | (209) 799 3113 | Windows, patio, painters | San Francisco · San Francisco County | — | — |
| Ace Automatic Garage Doors INC | Hernandez Miguel | — | (415) 826 7686 | Other | San Francisco · San Francisco County | — | — |
| Ace Drilling & Excavation | Ace Drilling & Excavation | — | (415) 730 6918 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Ace Drilling Engineering INC | Seosamh Padraig O Briain | — | (415) 730 6918 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Ace Glass & Door Company INC DBA Ace Building Services | Gregory Wayne Stanich | — | (415) 737 5300 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Ace Glass And Aluminum Company INC | Alex Pourshayegan | — | (415) 391 8400 | Windows, patio, painters | San Francisco · San Francisco County | — | — |
| Ace Painting INC | Foon Toy Hui | john@ace-painting.com | (415) 860 7139 | Windows, patio, painters | San Francisco · San Francisco County | — | — |
| Ace Plumbing & Rooter | Jonathan Neil Millington | — | (415) 824 6444 | HVAC | San Francisco · San Francisco County | — | — |
| Ace Roofing Company | James Yong Chom Chon | — | (415) 872 9300 | Other roofers | San Francisco · San Francisco County | — | — |
| Ace Roofing East Bay | Jun Jeffrey | — | (415) 524 5901 | Other roofers | San Francisco · San Francisco County | — | — |
| Ace Wiring Electric INC | Diego Gallegos | office@acewiringelectric.com | (415) 656 6954 | Electricians | San Francisco · San Francisco County | — | — |
| Acer-g Engineering | Leon Shi Kuang Zhang | — | (415) 724 3580 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Achill Beg Construction INC | James Patrick Gallagher | info@achillbegconstruction.com | (415) 643 4426 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Acme Bay Area Backflow INC | Mark Richard Delzer | — | (415) 505 3917 | Other | San Francisco · San Francisco County | — | — |
| Acme Builders | Acme Builders | — | (415) 573 5063 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Acme Roofing Company | Craig Joseph Lau | — | (415) 587 5869 | Other roofers | San Francisco · San Francisco County | — | — |
| Acon Built | Acon Built | info@aconbuilt.com | (415) 378 7950 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Acri Ddc | Acri Ddc | — | (415) 215 9634 | GC, remodel, ADU | San Francisco · San Francisco County | — | — |
| Active Scaffold | Juan Carlos Romero | active.scaffolding@hotmail.co.uk | (415) 912 7454 | Other | San Francisco · San Francisco County | — | — |
| Actnet Advanced Technology Corporation | Julie Yi Zhou | — | (415) 661 9000 | Other | San Francisco · San Francisco County | — | — |