Also if you want to upgrade your phone through Koodo, then you will need to pay off your tab first. If you buy an unlocked phone(or Koodo phone) from someone else, then you don't need pay off your tab.
Add: I saw your other post. If the phone you buy from someone that was also on koodo, then you can use your postpaid/monthly SIM and continue your service. It doesn't matter if that person was on prepaid :)
I have an iphone se with koodo that im selling, tab isnt fully paid off yet but i dont mind, anyways, do i personally have to go to koodo to get it unlocked or can the person im selling my phone to go get unlocked themselves ? And would a telus sim card work in any koodo phone and vice versa ?