Customers don't like to be transferred. So, before you transfer the call to another extension, make sure the other person is available and ready to help. Also, be sure you know how your system works so the customer will not get lost in a virtual switchboard, and remember to get their details and information before transferring, so you can call them back if needed.
Check out the video below on how to transfer calls properly:
Photo by Yan Krukov on Pexels: https://www.pexels.com/photo/a-woman-working-in-a-call-center-8867476/