One of the most common data entry errors are duplicate orders. Often users enter same Orders multiple times in the ERP system, which costs time in resolving the issue.
No tension in Compiere ERP. By enabling the Duplicate Verification process we can validate the Duplicate Order based on the No of days configured. Verification Process based on Partner, Product, and Qty level. During Order Processing, it will not allow to process the Duplicate Order.

Sales Order- Duplicate Order Verification

If you still need to process the Duplicate Order then by configuration changes at the Order level you can allow the Duplicate Order to be processed.
Compiere gives you the full flexibility to handling the Duplicate Order verification & Processing.

The following are the workflow for Duplicate Order Verification