| 2 M's Painting | 2 M's Painting | — | (818) 645 6453 | GC, remodel, ADU | Palmdale · Los Angeles County | — | — |
| 2 Sons Construction | Douglas Alan Ranabauer | — | (714) 681 3477 | GC, remodel, ADU | Covina · Los Angeles County | — | — |
| 20/20 Relining & Rooter | Roque Argote | — | (818) 403 8091 | Other | Palmdale · Los Angeles County | — | — |
| 200 Psi Fire Protection Co | Dong Hun Lee | — | (213) 763 0612 | Other | Northridge · Los Angeles County | — | — |
| 2010 Construction Co | Haghnazar Maghen Donay | — | (818) 632 2010 | GC, remodel, ADU | Encino · Los Angeles County | — | — |
| 2020 Building Services DBA Water Blasting Restoration | Salvador Jr Corona | — | (855) 842 2020 | Restoration | Burbank · Los Angeles County | — | — |
| 203K Contractors INC | Aaron Ron Baldwin | — | (323) 309 9722 | GC, remodel, ADU | Los Angeles · Los Angeles County | — | — |
| 20th Century Construction INC | David Bruce Siegel | — | (818) 887 2084 | GC, remodel, ADU | Calabasas · Los Angeles County | — | — |
| 21 Retrofit & Steel INC | Tony Jeong Kim | — | (213) 999 6286 | GC, remodel, ADU | Carson · Los Angeles County | — | — |
| 21 St Century Remodeling INC | Gabay Yosi | — | (818) 620 7190 | GC, remodel, ADU | Calabasas · Los Angeles County | — | — |
| 21st Century Electric M | Aharon Marcel Aharonian | support@21stcenturyelectricm.com | (323) 496 4155 | Electricians | North Hollywood · Los Angeles County | — | — |
| 21st Century Lihtc Construction INC | Scott Nichols Mason | — | (323) 231 4174 | GC, remodel, ADU | Burbank · Los Angeles County | — | — |
| 21st Century Painting | 21st Century Painting | — | (818) 517 1603 | Windows, patio, painters | Reseda · Los Angeles County | — | — |
| 21st Century Sterling INC | Stephen William Marvin | — | (310) 313 4633 | Electricians | Los Angeles · Los Angeles County | — | — |
| 220 Construction INC | Davit Simonyan | — | (818) 531 8449 | Electricians | Tujunga · Los Angeles County | — | — |
| 220 Electric INC | Simonyan Davit | — | (323) 531 8777 | Electricians | Tujunga · Los Angeles County | — | — |
| 23 1/2 Hrs Plumbing | Jesus Eduardo Arcos Ramirez | — | (323) 245 5246 | Other | Harbor City · Los Angeles County | — | — |
| 23bc Development | Jenn Tamayo Bareng | — | (747) 888 3400 | GC, remodel, ADU | Woodland Hills · Los Angeles County | — | — |
| 24 / 7 Electric | Luis Alonso Lopez | — | (626) 823 0498 | Electricians | Baldwin Park · Los Angeles County | — | — |
| 24 / 7 Fire Protection Services Incorporated | Richard William Jr Cronin | — | (562) 698 3830 | Other | Santa Fe Springs · Los Angeles County | — | — |
| 24 Hour Handyman And Contractor | 24 Hour Handyman And Contractor | — | (714) 955 7907 | GC, remodel, ADU | Long Beach · Los Angeles County | — | — |
| 24 Hour Rooter INC | Kheirian Diznab Ramin | — | (661) 400 1002 | Other | Palmdale · Los Angeles County | — | — |
| 24 Hour Water Damage | Nick James Angelopoulos | — | (626) 626 5543 | GC, remodel, ADU | Hacienda Heights · Los Angeles County | — | — |
| 24 Hours Garage Door And Gates Repair | Peretz Adi | — | (818) 205 4431 | Other | Winnetka · Los Angeles County | — | — |
| 24 Hr Plumbing | Luis Alberto Davila | — | (310) 973 2066 | Other | Lawndale · Los Angeles County | — | — |
| 24 Prefab LLC | Mario Salvatore Romano | — | (310) 243 6967 | GC, remodel, ADU | Santa Monica · Los Angeles County | — | — |
| 24 Rooter & Plumbing INC | Gabriel Jovani Robles | — | (626) 322 1538 | Other | Claremont · Los Angeles County | — | — |
| 24-7 Garage Door & Gate Services | Oded Termehi | — | (818) 805 7578 | GC, remodel, ADU | Encino · Los Angeles County | — | — |
| 24/7 Construction Works INC | Papaqui Juan Hernandez | — | (626) 536 8710 | GC, remodel, ADU | Los Angeles · Los Angeles County | — | — |
| 24/7 Garage Door Experts | Alexander Tchoubikin | — | (206) 619 9951 | Other | Los Angeles · Los Angeles County | — | — |
| 24/7 Leak Detection & Plumbing INC | Cesar Hugo Castellanos | — | (818) 808 7429 | Other | Mission Hills · Los Angeles County | — | — |
| 24/7 Rescue Plumbing Services INC | Jorge Luis Serrano-Barrientos | — | (818) 510 1204 | Other | Van Nuys · Los Angeles County | — | — |
| 240V Electrics | 240V Electrics | — | (747) 272 7796 | Electricians | Glendale · Los Angeles County | — | — |
| 247cctv INC DBA Etc Depot | Seog Soo Kim | — | (213) 278 0793 | Electricians | Los Angeles · Los Angeles County | — | — |
| 277 Electric | Juan Jose Resendiz | — | (310) 864 9728 | Electricians | Long Beach · Los Angeles County | — | — |
| 2by4 Construction Services INC | Mher Safrazian-Tabrizi | — | (747) 333 7402 | GC, remodel, ADU | Burbank · Los Angeles County | — | — |
| 2byforward INC | Julian Elmo David Seidenberg | — | (518) 821 4171 | Other | Sylmar · Los Angeles County | — | — |
| 2floor1 | Shifferman Erez | — | (818) 600 2009 | Other | Newhall · Los Angeles County | — | — |
| 2golden Construction | Ayar Negrete Ramon | — | (310) 430 3141 | GC, remodel, ADU | Compton · Los Angeles County | — | — |
| 2gun Roofing INC | Anthony Michael Tavera | — | (818) 245 2404 | Other roofers | Palmdale · Los Angeles County | — | — |