Hi,
There is a standard report from FI module, "S_ALR_87012341" - Invoice Numbers Allocated Twice
You can also check the duplicate items from BSIP table.
You can refer to the below link which shows the clear concept of duplicate invoice check
http://scn.sap.com/docs/DOC-35459
And the fields which are checked for duplicate are as follows: These items are checked together and if there is any change in any of the fields then the duplicate check will not be triggered.
- Company Code - 0001
- Vendor - TESTVENDOR
- Currency - EUR
- Invoice Date - 19.12.2012
- Reference document number - DUPL1
Hope this will be of help and would meet your requirement.
Regards,
Rithin