| Business | Phone |
| Arc Electric Frederick 21701 | (301) 620-9862 |
| Auspex Associates 5713 Industry Ln # 51, Frederick 21704 | (301) 631-5520 |
| Barclay Electrical Svc Inc 1920 Fieldstone Way, Frederick 21702 | (301) 696-1962 |
| Bopat Electric Co 305 E 4th St, Frederick 21701 | (301) 694-3726 |
| Brandenburg Electric Inc 700 N East St, Frederick 21701 | (301) 662-0144 |
| Crum Electric Co Inc 5748 Industry Ln, Frederick 21704 | (301) 663-3602 |
| Dixie Electric Co 6907 Baltimore Natl Pike # 9, Frederick 21702 | (301) 473-4665 |
| Doing Electric Inc 8995 Urbana Church Rd # A, Frederick 21704 | (301) 874-5505 |
| Electric Lain Llc 910 Walnut St, Frederick 21703 | (301) 620-0251 |
| Ercole Electric 601 W Patrick St, Frederick 21701 | (301) 663-0040 |
| Frederick Electric Co Llc 1786 N Market St, Frederick 21701 | (301) 695-7003 |
| Frederick Electric Svc Inc 33 E Patrick St, Frederick 21701 | (301) 663-6398 |
| Fredericktowne Electric 283 Pinoak Dr, Frederick 21701 | (301) 694-7986 |
| Grmsr Electrical Llc 4985 Winchester Blvd, Frederick 21703 | (301) 874-0501 |
| Horn Electric Svc Inc 416 E Patrick St, Frederick 21701 | (301) 662-8411 |
| Ipw Svc 1517 W Patrick St, Frederick 21702 | (301) 228-2396 |
| Maryland Electric Inc 417 W Patrick St, Frederick 21701 | (301) 682-5739 |
| Mid Maryland Elec Dist Inc 221 N East St, Frederick 21701 | (410) 775-7566 |
| Noah Electric 5515 Jefferson Pike, Frederick 21703 | (301) 695-4400 |
| Old Line Electric 410 Shannon Ct, Frederick 21701 | (301) 668-7177 |
| Power Systems Electric Frederick 21701 | (301) 663-7731 |
| Provident Electric Llc 6320 Quinn Rd, Frederick 21701 | (301) 620-2227 |
| Ricmar Electric Frederick 21702 | (301) 473-4723 |
| Royal Electric Svc Inc 6910 Bowers Rd, Frederick 21702 | (301) 473-5755 |
| Summit Electric Co 1 Mill Island Pkwy, Frederick 21701 | (301) 695-4694 |
| Trice Electric 4507 Metropolitan Ct # C, Frederick 21704 | (301) 662-6166 |
| Visual Electric Inc 5702 Industry Ln, Frederick 21704 | (301) 662-2444 |
| W E Davis Electric Inc 5112 Pegasus Ct # C, Frederick 21704 | (301) 694-5858 |
| Whfc Systems Inc 605 Winterspice Dr, Frederick 21703 | (301) 582-2535 |