Duplicate Invoice Detector — Stop Paying the Same Bill Twice

Duplicate-risk candidate register — illustrative

Preserve originals: A number INV-100; B INV 100; C INV-101. Normalization can compare separators while retaining source values and explaining the rule. Vendor identity V1 is supplied, not independently resolved.

Candidate A/B: strong duplicate-review hypothesis from same vendor, normalized invoice number, amount, currency and service period. Not confirmed liability or duplicate payment. Need originals, line items, dates, credit/rebill status and posting/payment records.

Candidate C: same amount but different invoice number and February period. Could be a legitimate recurring bill; no duplicate conclusion from amount alone.

Exposure framing: if A/B represent one obligation submitted twice, potential extra-payment exposure is $500, not $1,000. This is conditional; actual paid or payable amount unknown. Do not sum candidates without resolving overlap.

Review route: authorized AP owner checks document evidence and transaction state before retrying payment or applying a hold under policy. Preserve audit trail and separate exact submission duplication from economic obligation identity.

Preventive controls: stable vendor identity, raw/normalized invoice keys, service-period and credit/rebill checks, cross-channel ingestion deduplication and payment-state verification. Test false positives with legitimate recurring and partial bills.

Execution notes: no invoices opened, payment checked, hold placed, vendor accused/contacted or recovery initiated. No fraud or guaranteed recoverability claim.