| Business | Phone |
| Marshall Macklin Monaghan 80 Commerce Valley Dr E, Thornhill L3T 7N4 | (905) 250-5461 |
| Urs Cole Sherman & Assoc 75 Commerce Valley Dr E, Thornhill L3T 7N9 | (905) 882-4401 |
| Elecsar Engineering Ltd 7330 Yonge St #119, Thornhill L4J 7Y7 | (905) 881-8961 |
| Dipen Mukherjee & Assoc Ltd 55 Lambert Rd, Thornhill L3T 7E4 | (905) 889-3541 |