If I want to operate a customer's PC remotely, do we have to purchase two licenses, or is it enough if the customer has one license?
Thank you for your message.
Only one license is needed to enjoy full remote support with TeamViewer.
In other words, only one license has to be activated on one of the sides of the connection.
If you do or your customer does have already a license, you won't have any problems by supporting him.
I hope this could help. Do not hesitate to ask if you have more questions.