DEFINITION
Duplicate Payment
A duplicate payment is a second disbursement made for an invoice or obligation that has already been paid. It arises from exact re-entry of the same invoice, near-duplicate entry under a different vendor code or invoice format, or partial payments that together settle the same liability twice.
Exact duplicates — same vendor, same invoice number, same amount — are usually blocked by ERP controls at the point of entry. The leakage sits in near-duplicates: an invoice number entered as INV-1042 and again as INV1042, the same amount paid two weeks later under a new reference, or one supplier maintained under two vendor codes sharing a single bank account.
Because the patterns differ structurally, a single detection rule cannot cover them. Reliable duplicate payment detection combines exact matching, fuzzy matching on invoice references and amounts, cross-vendor matching on bank and tax attributes, partial-payment aggregation, and credit note reconciliation.