Please note that you cannot use your courier's online software in conjunction with ScrubBill.com.
If this is done you will see the "Waybill already exists" error returned by the courier.
For users that have already done this, you'll need to print out your waybills via the courier's online software as they do not exist within the ScrubBill.com environment.
If this was allowed your courier would be called twice for the same order - and you will be billed twice too!