Is it possible to delete all contacts?

Yes. You can easily delete all contacts uploaded to SurveyLab.

To delete all contacts :

1. Go to the  Contacts (Address Book) section and select the upper checkbox on a contact list.
2. Press SELECT ALL button.
3. Press  Delete button.
   
4. Press OK button to confirm the action.

NOTE. Please remember that by deleting the contacts from the contacts module (Address Book) you are deleting them also from all collectors. If you have an ongoing project it can impact them.