For registrations, one registration form completion equals one username and one registration record.  By registering with different email addresses, 2 different constituent/supporter records and ids will be created.  Do not merge the records, or the user will not be able to log in properly. Each registrant must have a unique email address. If multiple registrants register with the same email address, unexpected behaviors may occur. These unexpected behaviors include, but are not limited to the following:
  • All registrants with the same email address will be given the username of the registrant who signed up most recently. 
  • Password reset emails will only be sent for the username of the most recently registered participant
To deter this behavior:
  1. The participant should register for the event with Username A and the Email address A
  2. The participant should not use autofill.  He or she should register for the event again, but should use Username B and Email address B

Note: some email providers ignore a period in the email address. For example, if you have email address FirstnameLastname@gmail.com, you could register FirstnameLastname@gmail.com as registrant A, and then Firstname.Lastname@gmail.com for registrant B. Again, you will not want to merge these records. To Gmail, these are the same exact email address, but Sphere considers them unique.