CSV Import: Vendor Bill > Error: Multiple rows in your primary CSV file have the same value for the key column. Please edit this file to eliminate rows with duplicate key column values. for field "ExternalId"

Scenario: Customer imports vendor bill with expense line items using multiple files and External ID as the reference key, yet encounters an error: Multiple rows in your primary CSV file have the same value for the key column. Please edit this file to eliminate rows with duplicate key column values. for field "ExternalId" after field mapping and hitting the Next button.

 

Recommendation: Make sure that the Primary File - Vendor Bill does not contain more than one row with the same External ID.