---
name: invoice-duplicate-check
description: Detects possible duplicate supplier invoices by comparing invoice number, supplier, invoice date, currency, gross amount, purchase order, and line-item fingerprints, then separates exact duplicates from legitimate recurring charges. Use for invoice duplicate check, evidence review, management reporting, and decision support.
license: Apache-2.0
metadata:
  adlass.categories: "finance-accounting/accounts-payable"
  adlass.industries: ""
  adlass.tags: "invoice,duplicate,accounts-payable,supplier,matching,exception"
  adlass.adaptation: "reference-doc"
  adlass.source: "original"
  adlass.version: "1"
---

# Invoice duplicate check

## Purpose

Detects possible duplicate supplier invoices by comparing invoice number, supplier, invoice date, currency, gross amount, purchase order, and line-item fingerprints, then separates exact duplicates from legitimate recurring charges.

## Scope

Work only on the named source records and the deliverable fields described here. Preserve source wording, identifiers, dates, amounts, statuses, and citations. **Excluded:** contacting people, changing source systems, making approvals, or presenting a conclusion as a completed business action. The matching population is supplier invoices, not purchase orders, credit notes, expense claims, or recurring statements unless the source marks them as invoices.

## Data basis

- The process-specific documents, spreadsheets, and record tables in the skill scope.
- The company policy, rubric, control matrix, template, or prior-period output named by this process.
- Run-specific period, audience, project, or decision brief when supplied.
- The matching population is supplier invoices, not purchase orders, credit notes, expense claims, or recurring statements unless the source marks them as invoices.

## Result

Candidate pairs with match fields, rule, confidence, and citations. Invoice duplicate review {date}

## Quality criteria

- Every material fact and finding cites its document section, page, timestamp, table row, or record ID.
- Counts, amounts, dates, and statuses reconcile to the named source population.
- Rule outcomes show the rule and preserve source values beside normalized values.
- Missing, conflicting, excluded, and estimated items have explicit statuses.
- The written result and structured output use the same row-level findings.
- The matching population is supplier invoices, not purchase orders, credit notes, expense claims, or recurring statements unless the source marks them as invoices.

## Instructions

A duplicate candidate requires a shared supplier and matching evidence; recurring invoices with different service periods remain separate.

## Adapt before use
Use the invoice image or record citation for the decisive number, supplier identity, and service period; a matching amount alone is never sufficient to label a duplicate.
Use exact keys for supplier plus invoice number and near-match keys for supplier, currency, gross amount, and invoice date window. Compare purchase order and line-item hashes before assigning duplicate confidence.

- Add the company policy, rubric, control matrix, or approved format named in the Data basis.
- Map source column names, identifiers, status values, and date or currency conventions.
- Define the process threshold, escalation vocabulary, responsible review role, and retention rule.