Each license can only be activated on one device concurrently. That means to enable 2+ simultaneous users, you would need to purchase more licenses for each user.
If you would like to move your license to another device, such as new laptop or Office desktop to Laptop you can simply deactivate and reactivate.
To do this, first navigate to the PSEngine website at www.psengine.co.uk and click Log In:
Once you are logged in, or if you are logged in already, then navigate to Account>Purchases:
Scroll down to Subscriptions and select Manage key under License keys
Then simply click Deactivate Site
You can then activate the key on another device.