A custom countries.json file can add, change, or remove the countries that appear in menus within WHMCS and their calling codes.
The Localisation tab allows you to configure settings for the localization system.
The localization system allows WHMCS to display in WHMCS's many supported languages.
You can configure how dates display for admins and for clients.
You can customize text in WHMCS using the localization system.
You can choose whether to allow customers to select the language that they see in the Client Area from a list of WHMCS's supported languages.
You can choose the default country and language for your customers. WHMCS includes many supported languages.