Effects of identifier types

Some self-service capabilities are affected by the type of identifier(s) required.

Capabilities	'EMAIL' and 'USERNAME' both required	Only 'EMAIL' identifier required	Only 'USERNAME' identifier required
Self-service registration	Both supported identifiers are required by the customer to continue their registration journey.	The user only has to provide an email address at registration. The 'USERNAME' identifier might be included as an optional field or hidden altogether.	The user only has to provide an email address at registration. The 'EMAIL' identifier might be included as an optional field or hidden altogether. Customers could still add a 'primary emal address' to their profile information if an attribute is configured for that purpose, but that email address WON'T serve as an identifier.
Login	Although, both required at registration, customers can use either of their identifiers to identify themselves when logging in.	Customer can only identify themselves with their 'EMAIL' identifier.	Customer can only identify themselves with their 'USERNAME' identifier.
Account invitation	Account invitation are sent to customers via email. Customers can sign-up with the email address where the invitation is sent if the identity store supports the 'EMAIL' identifier.	Account invitation are sent to customers via email. Customers can sign-up with the email address where the invitation is sent if the identity store supports the 'EMAIL' identifier.	Account invitation are sent to customers via email. If only the 'USERNAME' identifier is required, the email address where the invitation is sent can't be used as an identifier
Account activation	If this self-service capability is enabled, customers receive account activation links to the email address they've provided as an identifier.	If this self-service capability is enabled, customers receive account activation links to the email address they've provided as an identifier.	In case of users who only have a ‘USERNAME’ identifier, account activation is ignored, even if the ‘EMAIL’ identifier was previously enabled. If the ‘EMAIL’ identifier is disabled in the identity store, the account activation email won’t be delivered, even if an ‘EMAIL’ identifier was provided.
Username reminders	Customers are asked to provide an email address when requesting a username reminder. If there's a matching email address in the identity store (an 'EMAIL' identifier or profile information) then the reminder will be sent.	If the ‘USERNAME’ identifier was displayed as an option at registration and the the user provided one, then they will be sent a username reminder. Username reminders are not available for users who only have ‘EMAIL’ identifiers. In this case, you can disable this capability in the related self-service policy.	Customers are asked to provide an email address when requesting a username reminder. If there's a matching email address in the identity store, in this case an email address in the customer's profile information, the reminder will be sent.
Self-service password reset	Password reset links are automatically sent to the 'EMAIL' identifier when a customer requests it. After the initial request, customers can re-request password reset to their phones if they have a confirmed phone number in their profile.	Password reset links are automatically sent to the 'EMAIL' identifier when a customer requests it. After the initial request, customers can re-request password reset to their phones if they have a confirmed phone number in their profile.	In case of users who only have a 'USERNAME' identifier, the password reset option is only available when a customer has a confirmed email address or phone number.
Account deletion notification	Customers are sent a follow-up email if they request an account termination in their self-service account. They receive an account deletion notification, and confirmation afterwards to the email address they have as an identifier.	Customers are sent a follow-up email if they request an account termination in their self-service account. They receive an account deletion notification, and confirmation afterwards to the email address they have as an identifier.	Customers are sent a follow-up email upon requesting account termination if they have an email address provided in their profile information. ⚠The account deletion notification is ignored if no email address is available which results in immediate account termination.