It depends whether your old supplier is using the One Touch switch scheme etc, @Nelson527.
Have you asked Talktalk to take over the same phone number?
If it's a mainstream (Openreach) ADSL or FTTC service, then it should be straightforward too.
But usually checking that the old supplier knows you are leaving is advisable! You should really be checking that company's cancellation guidelines.
Gliwmaeden2, a fellow customer.
