Thank you for contacting us with your issue.
To change the mobile phone number on an account you only need to know the email address and password to be able to change it.
> Enter your email address and password
> Select 'I cannot log in using my mobile phone' and click the link for 'change the mobile phone number you use to log in'
> Enter the mobile phone number you used previously > enter your NHS number > enter your new mobile phone number
OR select 'email you a security code' > enter your NHS number > enter your new phone number
You will then receive a text code to your new phone number to confirm the change.
Please note that it will take 24 hours before you can use the new phone number to log in.