Thank you ! Its strange they only asked postal code instead of whole address might be they have a record it seems !You have to register new SIN, and create new credentials. Immediately you can access your account but with limited access. You will get full access once you enter Security key that will receive in post in 10 business days. If urgent, call customer care select the option to get Security key in email. Once Agent verify some basic info, he will send the key in email and you can use it. Once you provide it in your CRA account, you will have full access.