# Collections accessible upon approval
To prevent misuse of your QR codes, you can add an approval level before trainees can access a collection. This can be particularly useful in the case of distance learning sessions.
## How to set approval on a collection
To activate this function, simply check the "**Needs approval**" box next to the collection name.
On the **Collections** page, collections needing approval will display a little padlock in the top right corner:
## Approval Flow
When a student fills out the identification form after scanning the QR code for a collection that requires pre-approval:
* A message will appear on their device, informing them that their access is pending approval from the instructor.
* The instructor will receive an email inviting him/her to approve or deny the student access in SENAR Studio:
* In SENAR Studio, the instructor will grant or deny access by clicking on either the green check or red X button.
* Once the instructor has granted access, an "Access Granted" message will appear on the student's device. The student can then install the simulators of the collection.
* If the instructor denies access, the pending user gets an "Access Denied" message and can't access the simulators. In this case, no token is debited from your account.
{% hint style="info" %}
You cannot withdraw access from a student after you have granted it. But if you have denied access in error, you can reverse your choice ([read more](https://support.senar.io/using-senar-studio/how-to-resolve-access-denied-in-error)).
{% endhint %}
