To be absolutely clear, you dont have to wait right until your renewal is about to happen to make the change, you can schedule the change to happen at your next renewal. Just be sure to choose the “Change At Next Renewal” option when you do it. Waiting until the last minute to make the change will quite likely lead to missing it for another month.
Do the change now by selecting “Change At Next Renewal” and it will be completed for you at your Next Renewal.
@Krystian : Do you mean "change of plan" as in moving over to another provider? ie. from elsewhere to here?
If Telus or Koodo then they can be suspended and be able to transfer to here. If elsewhere then they need to be active. I would suggest giving it a week depending on what kind of service. ie. voip, landline etc.
The best time to change a plan is on your NEXT renewal date.
When doing the Plan Change on self-serve, you'll be given the option of an immediate or on next renewal.
Always select next renewal to avoid missing out on what's been paid already on your existing cycle, as there's no refunds for partial cycles when switching plans mid-cycle.