I'm moving over to Zettagrid, do I have to cancel my NBN service with my current ISP?

I'm moving over to Zettagrid, do I have to cancel my NBN service with my current ISP?

Your previous ISP will be automatically notified when your NBN service is moved to Zettagrid however we do recommend contacting them upon completion of the move to ensure they have closed the service on their end.