@Anonymous User
Landline numbers, which I assume you are asking about, are allocated on a by-phone-exchange basis. So unless you are moving to somewhere really close by, you won’t get to keep your existing number.
That said, there are non-geographical numbers, but as far as I’m aware they are intended for businesses. If you had one, you would know.
You could always check with the broadband team to see if the number is transferrable to your new address.
