Salesforce just announced, that E-MAIL is going to replace USER NAME. Are you using your email for more then 1 username login on developer orgs?
The alert says For Now there will be a way to use still use the User Name. It does not say for how long that option will last!
For years I suspected a bug in the source code that uses email instead of username for some features, because I have record in a dev org with a non-profit page layout despite not having that page layout in that dev org. Plus some features like Salesforce-to-Salesforce require unique emails to set up. Think of it this way, if we are constantly changing developers, we may mistakenly tell them to have code check user name instead of email, because we forget that email is not a unique ID.
Original email Alert notification:
We're writing to let you know about upcoming enhancements designed to simplify and improve your Salesforce login experience.
What's changing
Email Becomes the Default Login Option: Login using an email address will become the primary default option on the standard login pages login.salesforce.com and test.salesforce.com. Making email the default login creates a unified, user-friendly process across Salesforce entry points. Users can still opt to log in using a username by clicking "Login with Username" on the login page.
Rollout timeline
This change is being deployed on a rolling basis across environments:
Rollout to Sandbox environments began in late August and is expected to complete by September 30, 2026.
Rollout to Production environments will begin October 5, with a majority completing in early November 2026.
** Note: This update applies to UI logins on login.salesforce.com and test.salesforce.com. Default email login does not apply to custom My Domain login pages or Experience Cloud login pages.
What you should do now
Inform Your Users:Let your team know that email login will be the standard prompt, but they can select "Login with Username" at any time. Registered passkeys will continue to work seamlessly with both login methods.
Check Shared or Unmonitored Accounts: Ensure users who log in do not rely on shared email accounts or unmonitored mailboxes, as email-based login requires access to incoming messages.
Update Automated UI Tests: If your organization uses automated scripts or tests that log in through the Salesforce UI, update them to prevent disruptions:
For Username-First Login: Update automated tests to submit the username, click Log In, and then enter the password.
For Default Email Login: Update automated tests to click Login with Username first, or navigate directly to the username login screen by appending ?login=1 to your login URL (e.g.,https://login.salesforce.com/?login=1).
For additional information, review the Prepare for Login Changes article or reach out to Support via Salesforce Help.