| Business | Phone |
| Ans Electric Inc 37 Edmund Seager Dr, Thornhill L4J 4S1 | (416) 678-0040 |
| Globrite Electric Co Ltd 50 Julia St, Thornhill L3T 4R9 | (905) 731-2057 |
| Kerr-Taylor Electrical Contrs 75 Glen Cameron Rd, Thornhill L3T 1N8 | (905) 889-2976 |
| Kva Electrical Systems Ltd 68 Jaimie Rd, Thornhill L4J 6A3 | (905) 669-4584 |
| Magum Electric 48 Dana Cres, Thornhill L4J 2R5 | (905) 709-2900 |
| N Watkin Electric Co Ltd 55 Worth Blvd, Thornhill L4J 7T1 | (905) 882-5474 |
| Quantech Electrical Contrs Ltd 17 Guardsman Rd, Thornhill L3T 6L2 | (905) 731-2343 |
| Raymar Electrical Sales 75 Glen Cameron Rd, Thornhill L3T 1N8 | (905) 889-2862 |
| Berg Electrical Contr 40 Proctor Ave, Thornhill L3T 1M5 | (416) 243-0110 |
| Big Ben Electrical Contracting 800 Steeles Ave W #B122, Thornhill L4J 7L2 | (905) 889-4133 |
| Sini Electric Ltd 139 Elgin St, Thornhill L3T 1W7 | (905) 764-8006 |
| Stonemill Electrical Ltd 11 Pearson, Thornhill | (905) 771-9147 |
| Summit Electric 7398 Yonge St #Ph1, Thornhill L4J 8J2 | (905) 707-9325 |
| West Electrical Contractors 2 Cedar Ave, Thornhill L3T 3V9 | (905) 889-7497 |
| West Electrical Inc 2 Cedar Ave, Thornhill L3T 3V9 | (905) 889-8254 |
| Branco Electric Co 49 Morley Rd, Thornhill L4J 2M8 | (905) 731-8441 |
| Cobra Power Inc 203 Langstaff Rd E, Thornhill L3T 3Z6 | (905) 763-1387 |
| D G Roberts Ltd 240 Romfield Circt, Thornhill L3T 3J4 | (905) 889-8822 |
| F Hams Electric 2900 Steeles Ave E #411, Thornhill L3T 4X1 | (416) 410-5727 |