Unable to login to ATT Email- "We've detected a SIM Card change"

Hi @jtb1818,

Thank you for reaching out to us! We understand that you're not able to log in to your AT&T email, and we're happy to assist you.

The error message you’re seeing, “We’ve detected a SIM Card change,” is usually displayed when there is a change in the SIM card of the device, you’re using to access your email account. We see that you've already tried using the other method “Try another way to use a different mobile number", but the code is going to the same number.

Please try using a desktop or laptop to log in to your AT&T email account. Please make sure to do the following before logging in:

• Open AT&T Mail in a different web browser. For example, if you normally use Google Chrome, try Firefox.
• Verify that your browser accepts cookies. If so, clear your cookies and cache. You’ll find this info in your browser's Preferences, Settings, or Options menu.
• Enable JavaScript, and make sure it’s up to date. You’ll find it in your browser’s Settings or Options menu.
• Disable browser tools or add-ons to see if they’re causing issues with email access.
• Enable Adobe Flash Player and make sure it’s updated.
• Check the settings of your firewall, antivirus programs, and anti-spyware software. They can cause a conflict with email programs and web browsers. Disable them one at a time and try to access your email. Don't forget to turn them back on once you know they aren’t causing the problem.

Also, please check out our guide that covers Open Authentication (OAuth) and secure mail keys. this will allow you to sign in with just a key on the desktop mail app of your choosing, rather than entering your password and a six-digit code on Currently.

Let us know how it goes.

For further assistance, we are always here to help!

Thank you for contacting AT&T Community Forum.

Nate, AT&T Community Forum Specialist.