| #1 Acoustics | Candice Diane Hanisch | — | (510) 489 2985 | Other | Hayward · Alameda County | — | — |
| #1 Door Stop INC | Freitas Susana De | — | (209) 647 2853 | Other | Manteca · San Joaquin County | — | — |
| #1 Honest Plumber INC | Edward Elesyado Hinojosa | — | (650) 422 4736 | Other | Sunnyvale · Santa Clara County | — | — |
| #1 Son Plumbing INC | James Lincoln Stanfield | — | (909) 904 3774 | Other | Highland · San Bernardino County | — | — |
| 1 - 2 - 3 Plumbing & Rooter | Eduardo Ramirez Alvarado | — | (818) 335 4935 | Other | Sherman Oaks · Los Angeles County | — | — |
| 1 - 877 Quikdry INC | Roger Arnold Christensen | — | (916) 985 8973 | Other | Folsom · Sacramento County | — | — |
| 1 - Adam - 12 Garage Door Service | Adam Scott Hudson | — | (916) 955 1410 | Other | Elk Grove · Sacramento County | — | — |
| 1 800 Pro-fence | 1 800 Pro-fence | — | (626) 221 9245 | Other | Monrovia · Los Angeles County | — | — |
| 1 Above Technology LLC | Yehuda Eliezer Netkin | — | (323) 325 6373 | Other | Los Angeles · Los Angeles County | — | — |
| 1 Day Aluminum Gutters | 1 Day Aluminum Gutters | — | (858) 472 6279 | Other | Poway · San Diego County | — | — |
| 1 Day Coatings Ie | 1 Day Coatings Ie | — | (909) 521 2171 | Other | Orange · Orange County | — | — |
| 1 Day Epoxy Flooring | Jay Franklin Goetz | — | (714) 322 3156 | Other | Anaheim · Orange County | — | — |
| 1 Day Rooter & Plumbing INC | Varuzhan Josh Balyan | — | (626) 696 9757 | Other | Hacienda Heights · Los Angeles County | — | — |
| 1 Demolition | 1 Demolition | — | (510) 229 6797 | Other | El Cerrito · Contra Costa County | — | — |
| 1 Oak Construction LLC | Dominique Haritzalde | — | (559) 206 3665 | Other | Clovis · Fresno County | — | — |
| 1 Source Material Handling INC | John M Howard | — | (818) 838 1688 | Other | Glendale · Los Angeles County | — | — |
| 1 Teamwork Fire Protection | Christopher Alan Cronin | — | (714) 309 2869 | Other | Newport Beach · Orange County | — | — |
| 1 Teamwork Fire Protection LLC | Austin Allen Holmes | — | (909) 390 8392 | Other | Rancho Cucamonga · San Bernardino County | — | — |
| 1 Tom Plumber Anaheim / Brea | Rickie Machie Moore | — | (714) 769 6300 | Other | Anaheim · Orange County | — | — |
| 1 Tom Plumber Concord | Dennis Earl Debenham | — | (925) 922 0594 | Other | Concord · Contra Costa County | — | — |
| 1-stop Integrated Solutions LLC | Luis Alberto Reyna Gaytan | — | (760) 705 5639 | Other | Escondido · San Diego County | — | — |
| 10-4 Millwork | Roger De Castro Ferreira | — | (650) 863 2333 | Other | San Mateo · San Mateo County | — | — |
| 10-4 Plumbing INC | Lopez Juan Davila | — | (951) 692 6355 | Other | Cherry Valley · Riverside County | — | — |
| 101 Cast Stone | 101 Cast Stone | sales@caststone.com | (805) 610 9278 | Other | Atascadero · San Luis Obispo County | — | — |
| 101 Concrete Company | Anguiano Isidro Torres | — | (805) 814 5379 | Other | Oxnard · Ventura County | — | — |
| 101 Concrete Services | Perez Humberto Rodriguez | — | (707) 344 2214 | Other | Bay Point · Contra Costa County | — | — |
| 101 Excavating LLC | James Mark Scobie | — | (805) 610 5161 | Other | Templeton · San Luis Obispo County | — | — |
| 101 Hardwood Flooring | 101 Hardwood Flooring | — | (760) 450 7429 | Other | Carlsbad · San Diego County | — | — |
| 101 Hauling Services | Abrahan Rodolfo Jaimes Duarte | — | (408) 874 5132 | Other | San Jose · Santa Clara County | — | — |
| 101 Paving Company | Francisco Xaiver Pelayo | — | (818) 370 4281 | Other | Littlerock · Los Angeles County | — | — |
| 101 Plumbing | 101 Plumbing | — | (805) 835 9807 | Other | Paso Robles · San Luis Obispo County | — | — |
| 101 Plumbing & Rooter | Marco Antonio Chavolla | — | (213) 393 8908 | Other | Los Angeles · Los Angeles County | — | — |
| 101 Plumbing Humboldt INC | Isaac Arizona Kennedy | — | (707) 498 2707 | Other | Eureka · Humboldt County | — | — |
| 101 Plumbing INC | Juan Hernandez Nunez | — | (805) 570 9816 | Other | Santa Barbara · Santa Barbara County | — | — |
| 101 Plumbing Repair Service | Jason Michael Turnidge | — | (805) 258 6458 | Other | Ventura · Ventura County | — | — |
| 101 Plumbing Solutions | Francisco Javier Zaragoza | — | (415) 377 6939 | Other | Petaluma · Sonoma County | — | — |
| 101 Seamless Gutters INC | George Eugene Angell | — | (707) 566 9113 | Other | Santa Rosa · Sonoma County | — | — |
| 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 Tile | 101 Tile | — | (805) 268 9379 | Other | Santa Maria · Santa Barbara County | — | — |