| Business | Phone |
| A-1 De Inc 1562 S Parker Rd # 220, Denver 80231 | (303) 752-0031 |
| Applied Optical Technologies 535 16th St # 920, Denver 80202 | (303) 534-4500 |
| Arko Executive Svc West 9725 E Hampden Ave # 100, Denver 80231 | (303) 671-5005 |
| Community Patrol/Investigation 1015 E Highway 224, Denver 80229 | (303) 940-0060 |
| Denver Metro Security 4995 Lowell Blvd, Denver 80221 | (303) 433-7777 |
| E & H Professional Security Co 7100 Broadway # 5f, Denver 80221 | (303) 427-2877 |
| Eps Security 1000 E 73rd Ave, Denver 80229 | (303) 289-2333 |
| Cognisa Security 8900 Pena Blvd, Denver 80249 | (303) 348-4725 |
| Cognisa Security Inc 6795 E Tennessee Ave, Denver 80224 | (303) 320-0470 |
| Contemporary Services Inc 1801 Mile High Stadim Cir 1000, Denver 80204 | (303) 850-0500 |
| Digitalsafe 45 Jackson St, Denver 80206 | (720) 941-6543 |
| Events Security Mgmt 2727 Bryant St # 550, Denver 80211 | (303) 477-0910 |
| Guardsmark Inc 4155 E Jewell Ave # 816, Denver 80222 | (303) 388-2800 |
| Ipc Intl Denver 500 16th St # 10, Denver 80202 | (720) 932-1796 |
| Top Dog Patrol 3320 W 2nd Ave, Denver 80219 | (303) 935-7274 |
| Twin City Security Inc 12015 E 46th Ave # 125, Denver 80239 | (303) 574-0000 |
| Spear Security & Patrol 181 E 56th Ave # 410, Denver 80216 | (303) 298-8373 |
| National Security Denver 80202 | (303) 298-9989 |
| Reliant Security 2175 S Jasmine St, Denver 80222 | (303) 758-3825 |
| Premier Security 20309 E 48th Dr, Denver 80249 | (303) 576-7198 |
| Penn Center Security Guard Sta 1301 Pennsylvania St, Denver 80203 | (303) 894-8316 |
| Brt Protective Svc 5400 W Jewell Ave # 1a, Denver 80232 | (720) 855-9246 |