@Anonymous User
As long as you are the account holder then you can change the email address on your account by getting in touch with the team via live chat or send a messaage, more details here
https://help.nowtv.com/article/how-to-change-email-address
Youll find the direct links to contact the team on this page
https://help.nowtv.com/contact-us/how-to-change-email-address
PS if your wife is the account holder then she will need to be the one getting in touch.
