I've been helping my elderly father with his BT account. When he tried to log in to his My BT account using his BT email as the BT ID, it failed. At first, we assumed he had misremembered the password.
Going through the "I can't remember my login details" path, he entered his landline number and answered the security question and was given his BT ID username. The username given is NOT a valid email address. That means when he tries to login using that username, it is rejected because it's not an email address.
So he is stuck. To change the BT ID username, he has to login to his account. But he can't login with the current username.
How can he get his BT ID username changed?
(It needs to be the same as his BT email address because he only has one email account. He can access his BT email account ok).