If there is two same invoices in Accounting, user need to "reject" one invoice. The steps are as follows:
  1. Please go to menu Accounting> Transactions> My Location's Transaction> please click Active button.
  2. Find an invoice that you want to "reject". If the invoice has been "approve", users are required to "unapprove" invoice in advance.
  3. After "unapprove" invoices, users can click the "reject" button at the top right of the page.
     Note: Invoices in Accounting can not be deleted, only can be "reject".