Add middle name on Personal Tax account

Dears Sirs, My full name is correct on my "Government Gateway" details but on my Personal Tax Account my full name is incomplete as my middle name is not included. How can I include my middle name on my Personal Tax Account details? Thanks for your help.

To be more specific my middle name is missing on “profile and settings” on my Personal Tax Account. Thanks again for your help.

Hi dmartinez,
You can use your Personal Tax Account (PTA) to change your name.
Select 'Your profile' from the top line of the PTA home page after you have signed in.
Select 'name change' link.
Select 'start now'.
You select 'Change of name' under change of circumstances.
Select 'Save and continue'
Thank you.