Hi Karen,
In the company profile for Adagio Invoices is a place to set the next invoice number and whether it auto-increments. Whenever a new invoice is created, the document number assigned there will be used and then incremented for the next invoice.
If after creating an invoice, someone goes back into the company profile and resets the 'next invoice number' back to one already used, then indeed a duplicate invoice number will be created. Also, if the invoice number is not 'locked' - another company profile option - then the entry person could edit the invoice number used and over-ride it with one that has already been used.
When copying or restoring invoices, there is an option to 'increment document number'. If you don't select this then the invoice number from the original document is copied to the new invoice - thus a duplicate unless it is changed.
In order to prevent duplicate numbers as best as possible, enable the option to 'lock' the invoice number from being edited, and only grant access to the Company Profile for the user(s) that should have it. And when copying or restoring invoices, always leave the 'increment document number' option enabled.
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Regards,
Softrak Tech Support