Can I use my emails address for more then one merchant account?

Payments OS does not allow to use the same email address for more then one Payments OS merchant account. 

For example: 

When using your email address [e-mail] to login to your merchant account "TreeU US" you will not be able to use the same email address [e-mail] to login to other merchant accounts you created, for example "TreeU UK".

In order to Login you will have to identify through a different email address (e.g: [e-mail]