Invoices: Warn for duplicate purchase order number

It would be great if Essentials like AccountRight would warn if you were entering the same Purchase invoice number.  Save time a reconciliation time cancelling all the double ups.  Please please please

Thank you for the idea. Unfortunately, this request has had no support from the community since it was submitted, so we are moving this idea to the Archived status. For more information on Idea Statuses, please read this article: Changes to our Idea Exchange pages