Each Plesk license subscription can only be activated for one IP address at any one time.
At certain point of time, you may be migrating your Plesk server to a new IP or when you are changing to a new service provider.
You can easily change the Plesk license IP that you have provided during the ordering process to a new IP by your own in the subscription control panel.
To change or modify the Plesk license IP:
The license will now be valid for the new IP address. Keep in mind your old IP license will now be no longer valid.