Payment Fraud Red-Flag Screener: Catch Bad Vendors Before the Money Leaves

The problem this kills

Most payment fraud doesn't look like fraud. It looks like a routine vendor whose bank details quietly changed last Tuesday, then got paid Wednesday. It looks like three invoices of $9,800 against a $10,000 approval limit. It looks like a "supplier" whose remittance address is a PO box that happens to match an employee's home, or a string of invoices numbered 1001, 1002, 1003 — a sign you're that vendor's only customer. Any one of these can drain real money, and by the time anyone notices, the wire has cleared and the trail is cold.

The maddening part is that the clues are already sitting in your data. The overlap between your vendor master and your employee directory is computable. The "bank changed, then paid within days" pattern is right there in the dates. Invoices that hug the approval threshold, repeat, or run in sequence are all detectable. What you need is something that checks every vendor and every payment against these known red flags before the run goes out — and hands a human the final call. You do not need to be a developer to build that.

What you'll build

A locked-down internal web tool for AP and audit. You import three files: your vendor master, your payments, and (optionally) an employee directory. The tool applies the classic fraud red-flag rules — employee-vendor bank or address overlap, banking details changed shortly before a payment, amounts that sit just under an approval threshold, duplicate and sequential invoice numbers, and PO-box-only vendors — and gives every vendor and payment a risk score with a plain-English reason for each flag. The controller reviews each flagged item and records a disposition: clear, investigate, or hold payment. Flags never auto-block a payment; a person always decides. On completion the tool exports a fraud-screening report and a hold/investigate list you can hand straight to whoever stops the run.

What's inside the Implementation Plan

The downloadable plan is a step-by-step file you paste into an AI coding agent. It opens by interviewing you about your business — your AP and approval process, the systems your vendor and payment data live in, the exact columns and naming in your exports, your real approval thresholds, your typical and peak payment volumes, and the edge cases that trip your team up. It reads a short spec back to you for a thumbs-up, then builds the tool around your answers instead of a generic template. From there it walks the agent through the data model, the three CSV imports, the red-flag rule engine and risk scoring, the controller's disposition screen, the human approval gate, and the report and hold-list exports. Because this tool touches PII (employee home addresses and bank details), the plan builds in restricted access and row-level security from the first step. Every step ends with a ready-to-copy prompt.

The governance it includes (this is the point)

This is an audit control, so it's built like one. The plan includes login so only your team can open it, row-level security so people only ever see their own organization's data, and tight handling of the sensitive fields — employee and bank data is restricted to the roles that need it. There's a complete audit trail of every flag and every disposition (who, what, when, and why), a hard human-in-the-loop gate so a flag can never block or release a payment on its own — the AI raises the suspicion, the controller decides — and duplicate guards so the same payment can't be screened or dispositioned twice. The whole tool exists to make a careful human judgment fast and defensible.

Who it's for

AP managers, controllers, and internal auditors who own the payment run and want a repeatable, evidence-backed way to catch fraud before the money moves. If you can describe what a suspicious vendor or payment looks like in your world, you can build this.

You've got this — open the plan, paste the first prompt, and you'll be screening your first real payment run this weekend.