This is the situation. I have an AdWords account which I use with my own email address. My girlfriend has another which she uses with her email address. However I am managing her ads for her so I want to be able to log into her AdWords and manage her account using my email address.
Annoyingly though when I gave myself admin access I was told I would need to use a new email address.
Buutt... I used to work with an agency that managed my AdWords; and all I did was give them access and as far as I know they were just able to log in using their own email address.
Has something changed with security recently for AdWords to allow (agents) to manage multiple clients AdWords from a single email?