2.11.9 User Guide

Retired Documentation

You are using the documentation for version 2.11.9. Go here for the latest version or check here for your available upgrades to the latest version.

Add Sites to MSM

When the Multiple Site Manager expansion is added to an ExpressionEngine installation, it enables the software to power up to 3 MSM Sites. Follow these steps to add more Sites to your ExpressionEngine installation.

Purchase Additional Sites

Pull up the manage purchases page in your account on (Make sure you’re logged into the same EllisLab account used to purchase the Multiple Site Manager license.) Next to the MSM license in question, you’ll see the option to Add Sites. Follow the checkout process in the store.

When you purchase additional Sites, your Multiple Site Manager files are automatically updated with the appropriate number of Sites.

Download New MSM Build

After completing the order, head back to your manage purchases page and download a copy of the Multiple Site Manager license with the newly added Sites. You’ll need this new MSM build to unlock the additional Sites in your software.

Upload to Your Installation

After unzipping the downloaded package, you’ll find a directory with these files:

  • system/expressionengine/libraries/Sites.php
  • system/expressionengine/controllers/cp/sites.php
  • system/expressionengine/language/english/sites_lang.php

Upload each of these files to their respective directories within your ExpressionEngine installation.

Now your installation will have the ability to power that many more MSM Sites. The next step is to set up the new MSM Site in your installation.


There is no explicit limit on the number of MSM sites that can be installed on a single installation of ExpressionEngine. However, there is a technical limit on the size of your MySQL database tables (see the MySQL documentation). This effectively limits the total number of custom channel fields, and thus ultimately the number of sites you can install. Depending on the types of fields and the MySQL storage engine, row size limits could pose a problem with anywhere between 500 - 2,000 custom fields. If you are concerned you may be using too many custom fields, our support team can help you decide whether more sites can be supported.