From my experience the access lasts for a "session", however long that may be. But before you even start you have to give them permission to have access. How you give that permission can vary with the type of access. In my case a banner popped up on my computer and you click on either "Accept" or "Decline". Also, there is usually something that indicates you are in shared mode. I saw a new icon in my menu bar. When sharing ended, the icon was gone. Also the type of access can vary. It could be just seeing what is on your screen all the way up to the ability to type and click. Of course if you are really paranoid or extremely cautious, you could imagine that a less honorable person could fake ending a session and still have access, which is why you should trust the company or person with whom you are dealing.


On a Mac since 1984.
Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.