Are you currently Koodo customer?(Monthly or prepaid?) If yes, you can remove SIM from current phone and put it to your old phone then restart your phone. If it uses different size SIM card, you will need to buy a new one and activate it through self serve.
I was a customer not anymore and it is a monthly phone. I just want to activate the phone again do I still need a new card or can I use the old sim card . If I need to buy one . We tried the local wallmart store wouldn't sell us a sim card without a contract