WHMCS is compatible with most web server environments that use PHP and MySQL®. However, before you can install or update WHMCS, you must ensure that your setup meets the system requirements for your chosen version. For example, before you can upgrade from WHMCS 8.8 to WHMCS 8.9, you must ensure that your system meets all of the system requirements for WHMCS 8.9.

• If you want to use the Automatic Updater, make sure that you meet our Automatic Updater requirements.
• Read the release notes for each version carefully. Upgrading dependencies in the wrong order may cause serious issues.
• Make sure to check the Marketplace listings for your custom modules. They may have additional requirements.

Supported Versions #

We currently support the following versions of WHMCS:

These releases are in the Active Development stage of our development cycle. All prior versions have reached End-of-Life (EOL) and we no longer maintain them or release updates for them, regardless of the reason. If you currently use an EOL version of WHMCS, we recommend updating to a supported version as soon as possible.

System Requirements #

To successfully run currently-supported versions of WHMCS, your system must meet the following requirements:

System Environment #

WHMCS is designed for a traditional LAMP (Linux, Apache, MySQL, PHP) environment that uses the standard Linux file system and cron subsystem. We validate WHMCS to run in Linux based environments running the Apache web server. Other environments like Windows®-based configurations will experience compatibility issues that WHMCS Technical Support does not support.

• Some WHMCS installations successfully use NGINX® instead of Apache, but we can only provide limited assistance with these systems.
• If you must use something other than the supported LAMP environment, consult with your hosting provider or system administrator to evaluate your system’s viability and long-term needs.

Apache Handlers #

You can choose to use virtual host handlers or server-wide handlers.

• Virtual host handlers (for example, suPHP or mod_ruid2) execute the PHP process as a specific user based on the domain name.
• Server-wide handlers (for example, CGI or mod_php) execute all PHP code as the same user.

Apache Directives #

WHMCS uses configuration directives in the following .htaccess files:

• The ~/.htaccess file contains the mod_rewrite directives that send routable paths through the index.php file. This allows the internal routing system to function and creates friendly URLs.
• The ~/vendor/.htaccess file prevents directly serving files from the ~/vendor directory while allowing WHMCS to access its libraries.

MySQL Database #

WHMCS requires MySQL for successful database operation. However, binary-compatible alternatives like MariaDB® may also work for some installations.

Database Privileges #

For the installation process, WHMCS requires the following database privileges:

ALTER     DROP      LOCK TABLES
CREATE    INDEX     SELECT
DELETE    INSERT    UPDATE

For daily operations, you can restrict WHMCS’s database by removing the ALTER, CREATE, DROP, and INDEX privileges. WHMCS only requires these privileges for installations, updates, and activating or deactivating modules.

Encrypted Database Connections #

Support for encrypted MySQL connections uses the following configuration variables in the configuration.php file. You can use the following variables:

• db_tls_ca — The path to the CA .pem file (for example, /var/www/html/whmcs/ca.pem).
• db_tls_ca_path — The path to the directory that contains the CA certificate files.
• db_tls_cert — The path to the client’s certificate.
• db_tls_cipher — A list of one or more ciphers to use for SSL encryption, in an OpenSSL-compatible format.
• db_tls_key — The path to the client’s key.
• db_tls_verify_cert — Disable (0) or enable (1) the server certificate.
  If you set db_tls_verify_cert to 1 (enabled), the db_host value in the configuration.php file must match the Common Name (CN) or be a Subject Alternative Name (SAN) of the certificate that you specify for db_tls_cert. If it does not match, you will see an error. For more information, see Could Not Connect Errors.

You can configure these variables before, during, or after installation using the command-line installation method or after installation using the browser-based installation method.

PHP #

Whenever possible, we recommend using a PHP version that is in active development or is receiving security fixes from upstream PHP maintainers.

• Issues in your PHP configuration can cause serious problems or prevent you from using certain features. For example, you may see warnings if the PHP version that the system cron uses does not match the web server’s version.
• Some features may have additional requirements. For example, the Automatic Updater requires specific PHP settings.

PHP Extensions #

In addition to the extensions above, WHMCS requires the default compiled extensions (for example, PDO, mysqlnd, JSON, libxml, DOM, or Fileinfo).

File Permissions #

The permissions settings that WHMCS requires depend on your exact system configuration. For example, we recommend the following permissions for a standard cPanel & WHM server:

• configuration.php — 400
• /crons/pipe.php — 755
• All other PHP files — 644
• All directories — 755

The file ownership and group should be the same as the user directory name. For example, on a cPanel & WHM server with a web root at /home/username/public_html/, username would own the files and the group would also use the name username.

The owner and group of the PHP process must be the same as the user directory name. For example, on a cPanel & WHM server with a web root at /home/username/public_html/, the PHP process owner and group would both be username.

For most WHMCS installations, we recommend the following permissions:

Last modified: June 14, 2024