Occassionally we come across the need to have two members added and both share an email address. This common occurs when a husbanda & wife just share one email account.
Since Process PA uses the email address as the unique identifier this causes a small issues.
Fortunately there is a work-around that will often suffice.
Outlook.com (Hotmail, live.com) and Gmail support a little known feature of + (plus) email aliasing.
What this allows is emails to be addressed to multiple addresses, but come into the same inbox, without any configuration.
Simplying if your email is firstname.lastname@example.org, you could use email@example.com or firstname.lastname@example.org and they would come to the same email.
This is typically used to aid filtering emails.
In Process PA however, simply add one user with the main email address, and the other with + alaising. They will both receive an email addressed to them if their email provider supports plus aliasing and can both log in and register attendance independently.