| Business | Phone |
| 77 Investigations 99 N San Antonio Ave # 240, Upland 91786 | (909) 946-8476 |
| Bob Heard's Investigation Svc 167 N 3rd Ave, Upland 91786 | (909) 931-5737 |
| Business Controls Inc Upland 91786 | (909) 985-6384 |
| Cramer Investigation Svc Po Box 1333, Upland 91785 | (909) 518-8080 |
| Melendez & Assoc 123 E 9th St # 303, Upland 91786 | (909) 981-2111 |
| Mendoza Investigation Svc Po Box 1854, Upland 91785 | (909) 931-4447 |
| Vincent Lozano Investigations Po Box 205, Upland 91785 | (909) 949-0179 |
| Watchman Investigations 1892 Wilson Ave, Upland 91784 | (909) 946-1065 |
| William Reese & Assoc Upland 91786 | (909) 949-4740 |