Duplicate Payment Pre-Run Checker: CSV Accounts Payable Hold Queue

Duplicate payments usually happen before anyone notices. A vendor name changes, an invoice number is typed slightly differently, a row is imported twice, or the same amount is approved by two people in the same payment cycle.

Duplicate Payment Pre-Run Checker is a downloadable CSV-first starter kit for accounts payable teams that want a practical review queue before releasing payments.

It compares:

- current payment run rows

- historical paid invoices

- optional vendor master aliases

It flags:

- exact duplicates already found in paid history

- invoice-number variations for the same vendor and amount

- same vendor and amount recently paid

- duplicate rows inside the current payment run

- vendor alias groups that can hide duplicate risk

Included in the download:

- Python duplicate-payment checker

- sample payment run CSV

- sample paid-history CSV

- sample vendor master CSV

- sample custom-column mapping file

- configurable rules file

- user guide

- column mapping quickstart

- buyer fit checklist

- demo walkthrough

- sample CSV, Excel, JSON, and HTML output reports

v1.1 adds custom column mapping and an Excel workbook output, so buyers can adapt ERP CSV exports without manually renaming every column.

This is a Starter Kit, not a hosted AP automation platform. It does not connect to your ERP, bank, card, or payment gateway. Buyers should be comfortable running a Python script locally or adapting CSV exports into the sample format.

Risk boundary: This product is a review assistant, not a replacement for payment approval, accounting controls, source document review, audit review, fraud detection, or professional judgment. It does not guarantee detection of every duplicate, overpayment, mismatch, or accounting error.