There is no reason you can’t carry passengers with you to an MOT appointment, in fact sometimes it could be advisable if you’re going to be sitting around at the test centre waiting for the results to come through as having someone to talk to is better than reading the same issue of whatever motoring magazine is lying around in the waiting room over and over again. A popular option is to have a friend follow you in their own car to the test centre so they can take you elsewhere, either back to work or to lunch, for example, so you’re not kicking your heels awaiting your result.