You can create an unlicensed user in Office 365 for testing purposes. Lets get started.
Prerequisites
Download and install the following modules.
- Microsoft Online Service Sign-in Assistant for IT Professionals RTW
- Windows Azure Active Directory Module for Windows PowerShell (64-bit version)
Create an Unlicensed User in Office 365 for Testing
- Open portal.office.com in your favorite web browser.
- Log in with global admin account or an account having required privileges.
- Open admin center dashboard by clicking on Admin.
- In the left pane, expand Users and then click 'Active users'
- Click '+ Add user'
- Enter all the details. In product licenses tab, toggle 'Create user without product license' to ON.
- Click Add and you are done.