authentication

Troubleshoot and resolve Oops! Access Denied - Forbidden errors while logging in to WHMCS.

Troubleshoot and resolve issues when an admin's Remember Me session ends and the system prompts them to log in again.

Troubleshoot and resolve issues with sessions not being removed.

Troubleshoot and resolve `OAuth authorization request denied due to unexpected active login session for 'Closed' User ID` errors.

Troubleshoot and resolve `Single Sign-On authentication denied for 'Closed' User ID` errors when attempting to use WHMCS single sign-on.

Troubleshoot and resolve `Single Sign-On authentication denied per configuration for User ID` errors when single sign-on is disabled.

Troubleshoot and resolve `Unable to authenticate with Single Sign-On token for User ID` errors during WHMCS single sign-on.

Before you can enable two-factor authentication (2FA) for users or admins, you must enable it globally for your WHMCS installation.

Configure two-factor authentication (2FA) for Admin Area logins. 2FA enhances security by adding a second step to the login process.

Configure two-factor authentication (2FA) for Client Area logins. 2FA enhances security by adding a second step to the login process.

You can restore access to the Admin Area or Client Area after the loss of a two-factor authentication (2FA) device and backup code.

If users or admins lose their two-factor authentication (2FA) device, they can regain access to WHMCS using their 2FA backup code.

After you enable two-factor authentication (2FA), you can require users and admins to configure it the next time that they log in to WHMCS.

Facebook® Sign-In Integrations let your customers register, sign in, and connect with your WHMCS installation.

Google® Sign-In Integrations let your customers register, sign in, and connect with your WHMCS installation.

Twitter™ Sign-In Integrations let your customers register, sign in, and connect with your WHMCS installation.