| Business | Phone |
| Alpha Royal Electric Corp 441 Esna Park Dr, Markham L3R 1H7 | (905) 947-4448 |
| Hart Electric Inc 2650 John St, Markham L3R 2W6 | (905) 947-0447 |
| Hi-Tech Electric 103 Empringham Cres, Markham L3R 3E9 | (905) 475-6123 |
| In-Sync Electrical & Controls 25 Valleywood Dr, Markham L3R 5L9 | (905) 513-2711 |
| Jtl & Son Ltd 190 Bullock Dr #16, Markham L6E 1A6 | (905) 294-7500 |
| Langstaff Electric 7321 Victoria Park Ave, Markham L3R 2Z8 | (905) 947-0525 |
| Leo Electric Inc 104 Beckenridge Dr, Markham L3S 3B1 | (905) 940-1911 |
| M H Electric Ltd 56 Miles Farm Rd, Markham L3S 2B2 | (905) 471-7850 |
| Mc Kinney Electric Ltd 176 Bullock Dr #17, Markham L3P 7N1 | (905) 294-8088 |
| Nab Electric Co 118 Adrian Cres, Markham L3P 7A8 | (905) 471-6622 |
| Noble Electric Ltd 155 Mcintosh Dr, Markham L3R 0N6 | (905) 479-6335 |
| Nvk Inc 8 Loweswater Ave, Markham L3R 7W4 | (905) 479-8831 |
| Beta-Tronic Ind Ltd 220 Royal Crest Crt, Markham L3R 9Y2 | (905) 475-5411 |
| Rosehill Electrical & Mech Inc 2600 John St #125, Markham L3R 3W3 | (905) 764-6172 |
| Standard Electric Inc 60 Esna Park Dr, Markham L3R 1E1 | (905) 475-6650 |
| Star Electric 147 Sophia Rd, Markham L3S 3Y9 | (905) 201-9275 |
| Stevens & Black Electrical 2600 John St, Markham L3R 3W3 | (905) 479-1885 |
| Uni Electrial & Mechanical Ltd 256 Denison St, Markham L3R 1B6 | (905) 477-7800 |
| W F Knapp Electric Co 33 Normandale Rd, Markham L3R 4J7 | (905) 475-9799 |
| Wire Electric 47 Norn Cres, Markham L3S 2A9 | (905) 472-9116 |
| Wiseman Electric Ltd 450 Alden Rd, Markham L3R 5H4 | (905) 479-2384 |
| York Electric Inc 83 Telson Rd, Markham L3R 1E4 | (905) 415-3999 |
| Econ Electric Co Ltd 24 Perdue Crt, Markham L3R 8T1 | (905) 479-7196 |
| Bronson Electric Co Ltd 85 Ferrier St, Markham L3R 2Y9 | (905) 477-8641 |
| Brothers & Wright Electrical 251 Amber St, Markham L3R 3J7 | (905) 477-0220 |
| Chuck Stokes Electric Ltd 21 Amberwood Crt, Markham L3R 9N2 | (905) 415-1984 |
| Clarke Electric 454 Raymerville Dr, Markham L3P 6K7 | (905) 294-8158 |
| Cougar Electric Ltd 70 Don Park Rd #10, Markham L3R 1G4 | (905) 477-1426 |
| Dan Tooley Electric 164 Krieghoff Ave, Markham L3R 1W3 | (905) 477-4769 |
| Electrostar Contracting Inc 250 Cochrane Dr #14, Markham L3R 8E5 | (905) 470-9162 |
| Duncan & Sons Ltd 10 Radford Cres, Markham L3P 4A1 | (416) 225-1955 |
| Elmartin Electrical Co Ltd 7321 Victoria Park Ave #22, Markham L3R 2Z8 | (905) 475-2030 |