| 4clover Construction | Wang Zhonghua | — | (626) 997 0077 | GC, remodel, ADU | Alhambra · Los Angeles County | — | — |
| 4creeks Build | Randy David Wasnick | — | (559) 372 0215 | GC, remodel, ADU | Visalia · Tulare County | — | — |
| 4D Construction | Ramirez Carmelo | — | (310) 908 5625 | GC, remodel, ADU | Azusa · Los Angeles County | — | — |
| 4D Milling INC | Chandler Joseph Anglin | — | (909) 709 7757 | Other | Oak Glen · San Bernardino County | — | — |
| 4D Surface Management INC | Michael Chris Doucette | — | (909) 797 0419 | Other | Yucaipa · San Bernardino County | — | — |
| 4d&n Landscaping INC | Daniel Alberto Flores Medina | — | (619) 410 2052 | Windows, patio, painters | Chula Vista · San Diego County | — | — |
| 4dream Builders INC | Alfonso Sr Mendez | aqremodeling2@gmail.com | (619) 416 4430 | GC, remodel, ADU | Chula Vista · San Diego County | — | — |
| 4ever Good Painting INC | Misael Antonio Sr Hernandez Huinac | — | (415) 574 8158 | Windows, patio, painters | San Rafael · Marin County | — | — |
| 4ever Painting | 4ever Painting | — | (909) 346 5224 | Windows, patio, painters | Rancho Cucamonga · San Bernardino County | — | — |
| 4ever Roofing INC | Ever Ernesto Hernandez | — | (916) 800 9962 | Other roofers | Elk Grove · Sacramento County | — | — |
| 4G Brothers LLC | Juan Luis Garcia Solano | — | (949) 200 0552 | Electricians | Fullerton · Orange County | — | — |
| 4G Builders INC | Juan Manuel Morales | — | (310) 995 8012 | GC, remodel, ADU | Lynwood · Los Angeles County | — | — |
| 4G Concrete Specialties INC | Kristin Julia Paulazzo | — | (925) 667 7257 | Other | French Camp · San Joaquin County | — | — |
| 4G Construction | Bolivar Fabian | — | (530) 681 5235 | GC, remodel, ADU | Woodland · Yolo County | — | — |
| 4G Grading | Gregory Douglas Garner | — | (760) 522 8920 | Other | Ramona · San Diego County | — | — |
| 4G Trenching | Garrido Humberto Olivares | — | (714) 597 5901 | Other | Orange · Orange County | — | — |
| 4gs Plumbing | Brad Zachary Gilkey | — | (805) 835 3024 | Other | Paso Robles · San Luis Obispo County | — | — |
| 4H Construction | Hayder Ali Radhi | — | (925) 788 1718 | GC, remodel, ADU | Roseville · Placer County | — | — |
| 4home Controls | 4home Controls | — | (626) 202 8011 | Other | Pomona · Los Angeles County | — | — |
| 4J Construction Services INC | Jerry Murphy Handy | — | (530) 588 9366 | GC, remodel, ADU | Sutter · Sutter County | — | — |
| 4j's Painting INC | Cesar Prudente-Berdejo | — | (559) 975 9338 | Windows, patio, painters | Madera · Madera County | — | — |
| 4je Plumbing | 4je Plumbing | — | (909) 638 9446 | Other | Fontana · San Bernardino County | — | — |
| 4K Patios | 4K Patios | — | (818) 287 1536 | GC, remodel, ADU | West Hills · Los Angeles County | — | — |
| 4K Pools | 4K Pools | — | (951) 522 3816 | Pool | Menifee · Riverside County | — | — |
| 4K Roofing | Jason Palmadge Stone | 4kroofing.socal@gmail.com | (951) 396 5419 | Other roofers | Eastvale · Riverside County | — | — |
| 4L Artistic Tile | Rudin Luis Roche | — | (415) 596 7043 | Other | Vallejo · Solano County | — | — |
| 4liberty INC | Srpouhi L Galpchian | — | (619) 559 1913 | Other | Encinitas · San Diego County | — | — |
| 4M Development Ventures INC | Gary Lee Mitchell | — | (530) 547 5875 | GC, remodel, ADU | Palo Cedro · Shasta County | — | — |
| 4M Plumbing | 4M Plumbing | — | (818) 399 9620 | Other | Sylmar · Los Angeles County | — | — |
| 4M Plumbing INC | Erick Estuardo Monterroso Mcclaughlin | — | (818) 399 9620 | Other | Sylmar · Los Angeles County | — | — |
| 4mar Construction INC | Marco Tulio Ramos Segura | guy@infinitydesignbuild.com | (619) 955 3207 | GC, remodel, ADU | San Diego · San Diego County | — | — |
| 4ourbath | Martin Gonzalez Vega | — | (323) 528 3598 | GC, remodel, ADU | Montebello · Los Angeles County | — | — |
| 4room | Eduard Aleksandrovi Yakovchuk | — | (916) 229 2700 | GC, remodel, ADU | Sacramento · Sacramento County | — | — |
| 4S Epoxy & Polish Concrete INC | Silvia Sanchez | — | (909) 270 6970 | Other | Ontario · San Bernardino County | — | — |
| 4sides Painting INC | Asadullah Khani | — | (619) 538 5874 | Windows, patio, painters | San Diego · San Diego County | — | — |
| 4sigma Home Development | Jawad Yousofi | — | (925) 525 5898 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| 4site Construction | Todd Ellis Wexman | — | (323) 905 6745 | GC, remodel, ADU | Los Angeles · Los Angeles County | — | — |
| 4T Contracting | Byron Matthew Woods | — | (559) 779 9991 | GC, remodel, ADU | Selma · Fresno County | — | — |
| 4th Amendment Fencing | Aaron Douglas Souza | — | (530) 949 7765 | Other | Cottonwood · Shasta County | — | — |
| 4th Dimension Drywall | 4th Dimension Drywall | — | (858) 568 3337 | Other | El Cajon · San Diego County | — | — |