how could I transfer old number after activation ?

Unfortunately you can't. You can only transfer your old number while you are signing up for the service. If you absolutely need your old number consider buying a new sim and activate it.

You can't, you need a new SIM and new plan. Given you can refer yourself, that's would cover that cost of a new SIM.

Hi Libby,

Is your number still active with your previous provider ? If you close an account without transferring it it may be lost. You should contact your previous provider in that case to ensure it is still available.

If you still have the number on a active account of yours, then you can go through the steps mentionned by Mike.

Unfortunately, you can’t.. open a new account maybe?

No, you cannot transfer your old number after activation. You can just cancel your subscription and then restart again. You can also ask for tech support if they can do something about it.

Libby,
Sorry, it's too late.
You must do it when you activate your new sim card.
Maybe, order another one with a new account and unsubscribe to your actual Fizz plan when you will activate the new sim card.