HOW TO: Force all logins for subsites to go througth the main site login

I am looking to force all users of subsites, to use the main site login, then redirect to their correct dashboard.

For example, if a user tries to login on the, they are forced to login via the

There is a chat over here about it, and a MOD posted a plugin from 2013 :

Is there a simple way to do this?

My setup is:
WP 4.7.3 - Subdomains
WPMU - Domain Mapping

  • Adam Czajczyk

    Hello redhillcreative,

    I hope you're well today and thank you for your question!

    The plugin that's been posted in that other thread is from 2013 because the entire thread is that old :slight_smile: The code however required only slight changes and it'd be the simplest way to achieve what you wish, I think.

    Here's the working code:

    if (is_multisite()) {
        add_action('login_head', 'redirect_to_main_login');
        function redirect_to_main_login() {
            global $blog_id;
            if (!is_main_site($blog_id)) {
                wp_redirect(trailingslashit(network_site_url()) . 'wp-login.php?redirect_to=' . trailingslashit(get_site_url()) . 'wp-admin');

    To use it on your site:

    1. create an empty file with .php extension (e.g. "my-login-redirect.php")
    2. copy and paste above code into it (using clean text editor such as e.g. Notepad++, Sublime or similar)
    3. save the file and upload it to the "wp-content/mu-plugins" folder of your site WP install

    If there's no "mu-plugins" folder inside "wp-content", just create one.

    I hope that helps!

    Best regards,