By default WHMCS will ban any IP address for a period of 15 minutes if they fail to login the admin area (invalid username and / or password) 3 times. This prevents people from being able to use multiple login combinations until they find one that actually works. You can alter the ban settings (minutes & the number of failed login attempts) by:
- Login your admin control panel
- Navigate to: Setup -> General Settings -> Security tab
- Enter the number of minutes for a ban to last, don’t set it too long or you may lock yourself out for quite a while should you make a mistake with your login details (Though you can remove the ban in PhpMyAdmin or whitelisting your IP as described below).
- Scroll down and click “Save Changes”