A warning if you have moved to BT - you may find your old provider has not closed your account
I moved to BT from Plusnet a number of weeks ago. According to the Plusnet terms of service (see below) I did not need to let them know as BT would do this. This did not happen in my case and I had to ring Plusnet to close the account.
If you are moving the service to another provider you don't need to contact us and MAC (Migration Authorisation Code) keys are no longer required to move between providers.
Please note that upon receipt of notification from a new provider that you wish to transfer your service, we will contact you to let you know the consequences of moving your service, including any applicable early termination charges.
To ensure no loss of service, your account will only be closed when we receive confirmation from our network supplier that the service has moved to the new provider.
When we receive confirmation that the transfer to the new provider has completed, our systems will automatically close your account.
If you don't receive confirmation of your account's closure once the transfer to the new provider has completed, you're advised to call our Customer Options team to inform us that your transfer has completed.