If I buy a Koodo cell phone, will it work with my Telus SIM card?
You can use your Telus Sim card in HTC One if it is a unlocked phone..To unlock your phone you can contact your service provider or use online service..Online service is recommended as you can unlock your phone from anywhere in the world..
I have experience in unlocking my phone with the help of Unlockzone.com where they provide you with unlock code and free instructions to unlock your phone.