An account can be deleted from the 'Pending Families' folder, but first you need to ensure that it has also been Zeroed Out.

Since no payments have been applied to the pending account, you can zero out the billing by:
  1. Navigate to Enrollment > Pending Families
  2. Click on the family name (blue hyperlink)
  3. Click 'Billing Details'
  4. Click 'Edit Billing Details'
  5. Click 'Zero Out Account' in the upper right 
  6. Enter a reason, then click Save Changes

​Then, to delete the family:
  1. Navigate to Enrollment > Pending Families
  2. Check box to the left of the family you wish to delete
  3. Click the blue 'Select Action' button and choose 'Delete Family'
  4. Click Submit in the pop up box
Note: If you need to undo the delete, you can follow the steps in the article How do I un-delete a family who was deleted during enrollment?