Can we have a warning added for when a purchase invoice number for the same supplier is duplicated. Eg, 2 copies of the same purchase invoice number exist, currently there is nothing stopping it from being entered twice (or more!) unless you have the time to diligently check the suppliers file for it.
Every other software I have used has this feature standard, even the old & bad ones.
When speaking with DEAR Support last week they advised the feature was not available for the reason of using the same invoice number across multiple supplier purchases. In my experience, each supplier purchase has it's own unique identifier (legal requirement) and does not/should not be duplicated. They may contain the same purchase order number across multiple invoice numbers but not the other way around.
If not a block (assuming someone has a reasonable use for the above DEAR response) then at least a warning/notification/prompt to check that they are not duplicating anything.