There are several potential solutions that could be used to resolve a scenario like this. But remember, only ever use one unique QR code for one unique location! You can hang multiple copies of the QR code poster in/around the entrance/exit of the location. This can be on either side of the door, along the wall of where normally a queue forms. A large scale printed banner/poster from the ceiling, or a sticker/mat on the floor. Also remember to place the signage prominently for entering and exiting the location.  It is also helpful to ask people to have the Consentry app open and ready to scan when they arrive and depart the location