How to create a mu-plugin (“must use” plugin)

A “Must-Use” plugins are special in WordPress – they cannot be disabled and run before any other plugin.

Being ran earlier is important when you need to ensure your code runs before another plugin.

To create a “Must-Use” plugin you will need access to the files and folders on your server – this may be through your web host’s “cPanel” account or FTP.

  1. Browse to the wp-content directory
  2. Create a new directory called mu-plugins – so you have /wp-content/mu-plugins
  3. Browse to the mu-plugins directory
  4. Create a new text file and give it an appropriate name followed by .php – for example itsg_mu_plugin.php
  5. This leaves you with /wp-content/mu-plugins/itsg_mu_plugin.php
  6. Edit the file and add the following to the top of the file (you can change the details to suit)
  7. <?php
    Plugin Name: must use plugins
    Description: code that is used always
    Version: 1.0.0
    Author: IT Support Guides
    Author URI:
  8. Save the changes – you now have a “Must Use” plugin!
  9. Code that you add to this plugin will be ran early in the WordPress loop – critically – before any other plugin is ran.


  • The main plugin file must be directly in the mu-plugins directory. Additional files can be in other folders.