| 40 Traffic & Construction INC | Steven Ray Forde | — | (530) 639 9987 | Other | Anderson · Shasta County | — | — |
| 4th Amendment Fencing | Aaron Douglas Souza | — | (530) 949 7765 | Other | Cottonwood · Shasta County | — | — |
| A & M Pressure Washing INC | Patty Mayer | — | (530) 244 4642 | Other | Redding · Shasta County | — | — |
| A - 1 Crane Service | Richard Le Roy Van Cleave | — | (530) 347 6947 | Other | Cottonwood · Shasta County | — | — |
| A C Framers INC | Jessaca Joleen Lugo | — | (530) 242 3930 | Other | Redding · Shasta County | — | — |
| A F P Sprinklers INC | Kenneth Edward Gonzalez | — | (530) 605 4760 | Other | Redding · Shasta County | — | — |
| A To Z Services | Miles Marvin Koenig | — | (530) 524 0464 | Other | Redding · Shasta County | — | — |
| A.r.c | Alexander William Ruess | — | (530) 209 0441 | Other | Redding · Shasta County | — | — |
| Aaron Keeran Construction | Aaron Knight Keeran | — | (530) 275 4564 | Other | Bella Vista · Shasta County | — | — |
| Abacus Construction INC | Garret Ryan Langum | — | (530) 215 3104 | Other | Redding · Shasta County | — | — |
| Abraham Baugh | Abraham Baugh | — | (530) 999 1647 | Other | Oak Run · Shasta County | — | — |
| Abrams Flooring | Abrams Flooring | — | (530) 440 2505 | Other | Redding · Shasta County | — | — |
| AC Tractor INC | Anthony Lee Cox | — | (408) 891 0983 | Other | Redding · Shasta County | — | — |
| Accent Quality Fence | Accent Quality Fence | — | (530) 365 8511 | Other | Cottonwood · Shasta County | — | — |
| Ace Low Voltage Systems | Ace Low Voltage Systems | — | (707) 478 0844 | Other | Shasta Lake · Shasta County | — | — |
| Acs General Engineering | Acs General Engineering | — | (530) 215 5628 | Other | Cottonwood · Shasta County | — | — |
| Adrian Renaud | Adrian Renaud | — | (530) 538 1614 | Other | Redding · Shasta County | — | — |
| Advanced Seamless Gutters Solutions | Advanced Seamless Gutters Solutions | — | (530) 980 6555 | Other | Redding · Shasta County | — | — |
| Ahern & Sons Plumbing INC | John Francis Ahern | — | (530) 221 7495 | Other | Redding · Shasta County | — | — |
| Alcon Engineering | Araiza Victor Vazquez | m.congedo@alcon-engineering.com | (650) 315 3342 | Other | Cottonwood · Shasta County | — | — |
| Alex Voorhees | Alex Voorhees | alex@alexvoorhees.com | (530) 410 2089 | Other | Redding · Shasta County | — | — |
| All Floors | All Floors | — | (530) 921 9037 | Other | Redding · Shasta County | — | — |
| All Good Hardwood Floors INC | Anthony Sergio Gonzalez | — | (530) 262 1192 | Other | Redding · Shasta County | — | — |
| All Plumbing & Drain Solutions | All Plumbing & Drain Solutions | — | (530) 275 5105 | Other | Redding · Shasta County | — | — |
| All State Fencing | All State Fencing | — | (530) 710 6496 | Other | Redding · Shasta County | — | — |
| Allen Berlt's Rock Wall's | Allen Berlt's Rock Wall's | — | (916) 879 0553 | Other | Burney · Shasta County | — | — |
| Alliger Plumbing & Fire Protection INC | Kylin Edward Alliger | — | (530) 604 6516 | Other | Redding · Shasta County | — | — |
| Alpha Communications LLC | Derek Cole Lynch | — | (530) 941 3217 | Other | Redding · Shasta County | — | — |
| Alva's Carpet Laying | Alva's Carpet Laying | — | (530) 274 2274 | Other | Redding · Shasta County | — | — |
| Alvarez Lathing & Plastering INC | Alvarez Pedro Alvarez | — | (530) 351 5319 | Other | Redding · Shasta County | — | — |
| Aments Anytime Plumbing | Aments Anytime Plumbing | — | (530) 347 5030 | Other | Cottonwood · Shasta County | — | — |
| American Concrete Placement Company | Brian Paul Kamisky | — | (530) 378 5317 | Other | Anderson · Shasta County | — | — |
| American Door Company INC | William George Jr Fuentes | — | (530) 224 1640 | Other | Redding · Shasta County | — | — |
| American Flooring Installations INC | Larry Paul Marvel | — | (530) 227 4361 | Other | Redding · Shasta County | — | — |
| American Leak Detection | Joseph Bennett Bates | — | (530) 222 5325 | Other | Redding · Shasta County | — | — |
| American Traffic & Safety INC | Antoinette Ranee Donnelly | — | (530) 209 9276 | Other | Anderson · Shasta County | — | — |
| Andrew Brundage Cabinetry | Andrew Lee Brundage | — | (530) 999 1730 | Other | Redding · Shasta County | — | — |
| Angel Engineering Constructor's | Angel Engineering Constructor's | — | (530) 410 5170 | Other | Shasta Lake · Shasta County | — | — |
| Angelos Plumbing Services LLC | Angelo Saverio Duran | — | (530) 782 4033 | Other | Redding · Shasta County | — | — |
| Anthony's Window Cleaning | Anthony's Window Cleaning | — | (530) 524 0174 | Other | French Gulch · Shasta County | — | — |