> [!IMPORTANT]
> Making email optional is a user flow–level setting. This change applies to sign-ups for **all applications** associated with the user flow.
> [!NOTE]
> When email isn't collected, email one-time passcode (OTP) can't be used for MFA. Make sure an alternative MFA method (such as SMS) is enabled if your policies require MFA.
> [!TIP]
> The account picker typically displays the user's email address. When no email address is collected, the display name is shown instead. To help users easily identify their account, map the `name` claim in [Claims mapping](reference-oidc-claims-mapping-customers.md) or collect display name during sign-up.
- Users can't register an MFA method and can't complete sign-in, and often encounter an error.
- Users aren't redirected to the MFA registration (sign-up) flow during sign-in as expected.
- A user created without an email address can't register an email address for use with email one-time passcode (OTP) as an MFA method.
## Related content
> [!IMPORTANT]
> Making email optional is a user flow–level setting. This change applies to sign-ups for **all applications** associated with the user flow.
> [!TIP]
> The account picker typically displays the user's email address. When no email address is collected, the display name is shown instead. To help users easily identify their account, map the `name` claim in [Claims mapping](reference-oidc-claims-mapping-customers.md) or collect display name during sign-up.
- Users can't register an MFA method and can't complete sign-in, and often encounter an error.
- Users aren't redirected to the MFA registration (sign-up) flow during sign-in as expected.
## Related content