I just received an email from Google about upcoming changes to the maximum number of users for Google Apps. When Google Apps was released, Google allowed all accounts to create up to 500 users. The limit was changed in 2009 for free accounts and reduced to 50 users.
Today, Google is changing this limit again to 10 users. Here's the content of the email.
We recently announced upcoming changes to the maximum number of users for Google Apps. We want to let you know that, as a current customer, the changes will not affect you.
As of May 10, any organization that signs up for a new account will be required to use the paid Google Apps for Business product in order to create more than 10 users. We honor our commitment to all existing customers and will allow you to add more than 10 users to your account for DOMAIN at no additional charge, based on the limit in place when you joined us.
The Google Apps Team
Starting from 10 May 2011, the new maximum number of users for a Google Apps for free account will be set to 10.