Best answer by Dinh
You should be able to make conference call with your iphone using Koodo. The instruction is here https://support.apple.com/kb/TA38608?locale=en_US&viewlocale=en_US
- Place a call.
- From the in-call menu, tap Add Call. While you dial the second number, the first call will be placed on hold. If you don't see the in-call menu, tap the Hide Keypad button to bring it up on the screen.
- Once you have the other person on the line, tap Merge Calls to connect everyone.
- Repeat steps two and three to add other people to the conference.