Change the bank account you pay your Direct Debit from, change your payment date or cancel your Direct Debit.
Here are some answers to help you
Change or cancel your Direct Debit
How can I pay my BT bill?
Pay your BT bill with Direct Debit, online in My BT or the My BT app. You can also pay by phone, cheque or in person at a PayPoint. What to do if you can't pay your bill.