| 101 Sheet Metal INC | Arnold Gysbertus Jr Scherpenborg | accounting@sheet-metal.com | (805) 499 7444 | Other | Newbury Park · Ventura County | — | — |
| 101 Stucco INC | John Hugh Coutts | — | (760) 801 2639 | Other | Encinitas · San Diego County | — | — |
| 101 Terra General Engineering | 101 Terra General Engineering | — | (831) 682 5519 | Tree | Seaside · Monterey County | — | — |
| 101 Tile | 101 Tile | — | (805) 268 9379 | Other | Santa Maria · Santa Barbara County | — | — |
| 101 West Coast INC | Glenn Howard Stern | — | (818) 613 8567 | GC, remodel, ADU | Encino · Los Angeles County | — | — |
| 101 West Painting | 101 West Painting | — | (818) 579 3853 | Windows, patio, painters | Santa Clarita · Los Angeles County | — | — |
| 1010 Electric | Matt Mohammad Sohrabi | — | (760) 807 5555 | Electricians | San Marcos · San Diego County | — | — |
| 1015 Construction | Arthur Charles Mansir | — | (760) 415 4245 | GC, remodel, ADU | Escondido · San Diego County | — | — |
| 1016 Electric | Giovanni De Jesus Rizo Garcia | — | (951) 437 8485 | Electricians | San Jacinto · Riverside County | — | — |
| 104 Air Heating And Cooling LLC | Martin Tejeda | — | (559) 567 3808 | HVAC | Madera · Madera County | — | — |
| 108 Mechanical | 108 Mechanical | — | (209) 648 2371 | HVAC | Knights Ferry · Stanislaus County | — | — |
| 10perature Heating And Air Conditioning | Perez Abraham Perez | — | (714) 610 4733 | HVAC | Garden Grove · Orange County | — | — |
| 10square Construction INC | Patrick Bai Lam | — | (510) 501 1827 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| 10ten Construction LLC | Jessica Marie Gilmour | — | (760) 712 7840 | GC, remodel, ADU | Fallbrook · San Diego County | — | — |
| 10X Painting INC | Juan Carlos Magana | — | (650) 269 2316 | Windows, patio, painters | Sunnyvale · Santa Clara County | — | — |
| 10x33 Construction Consulting | Zakar Gamaliel Jayne | — | (619) 995 1023 | GC, remodel, ADU | San Diego · San Diego County | — | — |
| 11 11 Heating And Cooling | 11 11 Heating And Cooling | — | (909) 728 0848 | HVAC | San Bernardino · San Bernardino County | — | — |
| 11 Concrete And Paving INC | Apodaca Gerardo Burgos | — | (408) 690 4619 | Other | Milpitas · Santa Clara County | — | — |
| 11 Electric LLC | Wes Bruce Farnsworth | — | (310) 948 8701 | Electricians | Marina Del Rey · Los Angeles County | — | — |
| 110 Lavant INC | Janelle Alize Ramos | — | (310) 880 5657 | GC, remodel, ADU | Torrance · Los Angeles County | — | — |
| 110 Pro HVAC INC | Messbah Dast Gheib | — | (818) 590 6886 | HVAC | Encino · Los Angeles County | — | — |
| 110/220v Electric Co | Bart Steven Speccia | — | (650) 784 1886 | Electricians | San Bruno · San Mateo County | — | — |
| 111 Construction INC | Keyork Ohannes Ayarian | — | (818) 535 3111 | GC, remodel, ADU | Northridge · Los Angeles County | — | — |
| 111 Painting And Decorating | Haro Samuel Bernal | — | (760) 308 7590 | Windows, patio, painters | Coachella · Riverside County | — | — |
| 1111 Construction | Chad Edward Emery | guy@infinitydesignbuild.com | (760) 420 7236 | Electricians | Vista · San Diego County | — | — |
| 1111 Heating And Air Conditioning | Jr Ubaldo Franco | — | (951) 963 6305 | HVAC | Corona · Riverside County | — | — |
| 1111 HVAC Services LLC | Jesse Clayton Anderson | — | (951) 519 3211 | HVAC | Menifee · Riverside County | — | — |
| 1153 San Rafael LLC | Najjarian Raman | — | (408) 712 4692 | HVAC | San Jose · Santa Clara County | — | — |
| 11B INC DBA Yourdeckbuilder.com | Matthew William Thompson | — | (323) 963 3257 | GC, remodel, ADU | Burbank · Los Angeles County | — | — |
| 11B Renewables INC | Otto Ivan Pena | — | (213) 479 5960 | Electricians | Fullerton · Orange County | — | — |
| 12 Bravo Development INC | Woo Sangin | — | (626) 423 2732 | GC, remodel, ADU | Santa Fe Springs · Los Angeles County | — | — |
| 12 One 12 Renovations | 12 One 12 Renovations | — | (562) 313 9990 | GC, remodel, ADU | San Pedro · Los Angeles County | — | — |
| 12 Rivers Construction | Michael Bruce Stonehocker | arielle.pennington@riversconstruction.com | (408) 206 8909 | GC, remodel, ADU | Hollister · San Benito County | — | — |
| 12 Stone Construction Co | Caesar Carlos Evangelista | — | (352) 217 6490 | GC, remodel, ADU | San Bruno · San Mateo County | — | — |
| 120 West Construction | Justin Leroy Chavez | — | (805) 878 4724 | GC, remodel, ADU | Santa Maria · Santa Barbara County | — | — |
| 1224 INC | Jamison Scott Persons | — | (619) 206 0811 | Other | San Diego · San Diego County | — | — |
| 123 - Floor INC | William Brent Powell | — | (415) 485 1230 | Other | San Rafael · Marin County | — | — |
| 123 Construction | John William Jr Faber | — | (909) 941 5200 | GC, remodel, ADU | Rancho Cucamonga · San Bernardino County | — | — |
| 123 Construction LLC | John William Jr Faber | — | (909) 941 5200 | GC, remodel, ADU | Rancho Cucamonga · San Bernardino County | — | — |
| 123 Floor | James Wendell Cantwell | sdjim6@gmail.com | (858) 583 0377 | Other | San Diego · San Diego County | — | — |