Activating the duplicate check for vendor invoices and credit memos in SAP helps prevent duplicate postings, reducing financial discrepancies and errors.

Below are the steps to enable it

Step 1. Activate Duplicate Check in SAP Configuration (SPRO)

Path : SPRO --->Sap Ref IMG--->Materials Management--->Logistics Invoice Verification--->Incoming Invoice--->Set Check for Duplicate Invoices.

Step 2. Define Duplicate Check Criteria in Vendor Master Data

Enter T-code BP (FLVN00 Supplier FI )

Step 3 Enable Duplicate Check in Document Entry (FB60, MIRO)

When entering invoices via FB60, MIRO, or F-43, SAP will check for duplicate entries based on the defined criteria.

If a duplicate is detected, SAP will generate a warning or error message (depending on configuration).

You can set the system behavior for duplicate invoices

• Warning Message: User can proceed with posting.

• Error Message: Prevents posting of duplicate invoices

Change Message Control for Vendor Master Data

path : spro --->sap Ref Img--->Financial Accounting --->Accounts Receivable and Accounts Payable--->Supplier Accounts---> Vendor Master Data ---->Change Message Control for Vendor Master Data

Enter Application Area F5

Enter Application Area M8

Transactional Data 1 : For Illustrating Duplicate invoice check Process.

Enter Vendor Invoice using T-code FB60

In the Example an invoice is posted against a vendor with Following Parameters.

Company code : RELC

vendor : 1000000005

Currency : INR

Invoice Date : 26.03.2025

Reference Document Number : TEST 2

Document Posted with Number 1900000002 , lets try to post another vendor invoice with same parameters

System is Giving an Error : Check whether document has already been entered under number RELC 1900000002 2024.

Thank you