invoice-validator-mcp

# Invoice & Payment ID Validator — remote MCP server

**Ask one question before paying an invoice: pay, review, or hold?** `check_invoice_payee` takes whatever the invoice has (IBAN, BIC, VAT, EIN) plus the supplier's country, and returns a verdict with plain-English reasons.

## What makes it different

Most IBAN/VAT APIs check each number on its own: "this IBAN is well-formed". That misses the real invoice-fraud signal, which is a **mismatch between numbers that are each valid**:

- **Changed bank details**: your German supplier's invoice asks for payment to a Dutch or Lithuanian account. Every ID is valid; the verdict is `hold`.
- **BIC from a different country than the IBAN**: the two don't belong to the same account.
- **VAT registered to someone else**: with `live=true`, the VIES-registered company name is compared with the supplier name.
- **Unregistered VAT, test BICs, EUR invoices paid to non-SEPA accounts.**

Example (live, from the free demo endpoint):

```json
{"verdict":"hold","risk_score":90,
 "summary":"Hold payment: BIC is from DE but the IBAN is from NL ...; Supplier is in DE but wants payment to a NL bank account: the classic changed-bank-details fraud pattern. Confirm by phone using a known number."}
```

It is also **MCP-native with a free, keyless demo endpoint**, so an agent can try it in one config line. Single-ID validators are included too.

## No-code version

Not building an agent? The same checks come in ready-made tools:

- **[Free IBAN & VAT checker](https://invoice-validator.mohamed-bahaa53000.workers.dev/tools/iban-vat-checker)** in your browser, with no sign-up.
- **n8n templates:** [AP Invoice Triage (free)](https://mohabaha0.gumroad.com/l/ap-invoice-triage-free) pulls Gmail PDF invoices into Google Sheets with Gemini, and [AP Invoice Triage Pro ($69)](https://mohabaha0.gumroad.com/l/ap-invoice-triage-pro) adds the approval workflow.
- **[Done-for-you setup ($149)](https://mohabaha0.gumroad.com/l/n8n-setup):** I install and configure it in your n8n.

## Try it free

- **No key, right now:** point any MCP client at `https://invoice-validator.mohamed-bahaa53000.workers.dev/demo/mcp` (10 tool calls per IP per day).
- **Free RapidAPI plan:** 100 requests/month on the [Basic plan](https://rapidapi.com/MohamedBahaa/api/invoice-payment-id-validator/pricing), no card needed. Pro is $10 for 10,000.
- **Pay per call, no account (x402):** agents with a USDC wallet on Base can pay $0.01 per call at `https://invoice-validator.mohamed-bahaa53000.workers.dev/x402/v1/payee-check` (also `/x402/v1/iban`, `/bic`, `/vat/eu`, `/vat/gb`, `/ein`). `GET /x402` shows the terms; an unpaid call returns HTTP 402 with the payment requirements.
- **Using n8n?** Get [AP invoice triage installed in your n8n for $149](https://mohabaha0.gumroad.com/l/n8n-setup), done for you.

This is a **hosted (remote) MCP server** using Streamable HTTP. There is nothing to install or run locally, and this repository holds documentation and the MCP Registry manifest only. The server code is not open source.

| Endpoint | Auth | Limits |
|---|---|---|
| `https://invoice-validator.mohamed-bahaa53000.workers.dev/demo/mcp` | none | free, 10 tool calls per IP per UTC day, no batch |
| `https://invoice-payment-id-validator.p.rapidapi.com/mcp` | `X-RapidAPI-Key` + `X-RapidAPI-Host` headers | paid per request via [RapidAPI](https://rapidapi.com/MohamedBahaa/api/invoice-payment-id-validator) (free Basic plan available) |

Official MCP Registry name: `dev.workers.mohamed-bahaa53000.invoice-validator/invoice-payment-id-validator`

## Tools

- `check_invoice_payee`: **pay / review / hold** verdict, risk score, reasons, and per-ID results. Inputs (all optional, at least one ID): `iban`, `bic`, `vat`, `ein`, `supplier_country`, `supplier_name`, `currency`, `live`.
- `validate_iban`: mod-97 checksum, length for its country (100+ countries), SEPA membership; returns normalized/formatted IBAN, country, BBAN, bank/branch/account parts where known, or machine-readable error codes.
- `validate_bic`: BIC/SWIFT structure (8 or 11 chars), ISO country, test-BIC flag; pass `iban` to check the BIC country matches the IBAN country.
- `validate_eu_vat`: EU VAT ID (27 member states + XI) format and check digit offline; `live=true` also queries EU VIES for registration status, name and address (VIES failures return `vies.checked=false`, never a false "invalid").
- `validate_gb_vat`: UK VAT number format, types and HMRC mod-97 / 9755 checksum.
- `validate_ein`: US EIN 9-digit format and valid IRS campus prefix (EINs have no check digit, so this catches typos and fake prefixes, not every invalid number).
- `validate_batch`: many identifiers in one call (**paid endpoint only**).

## Use cases

- Accounts-payable agents: run `check_invoice_payee` on every invoice and only auto-pay `pay` verdicts.
- Accounts-payable agents: verify supplier IBAN/BIC and VAT IDs before approving a payment run.
- Catch IBAN typos and BIC/IBAN country mismatches (a common fraud signal).
- Vendor onboarding: confirm an EU VAT ID is registered in VIES.

## Connect

Claude Desktop / Cursor / Cline / VS Code (any client that supports remote Streamable HTTP servers):

```json
{
  "mcpServers": {
    "invoice-validator": {
      "url": "https://invoice-validator.mohamed-bahaa53000.workers.dev/demo/mcp"
    }
  }
}
```

Paid / production (RapidAPI):

```json
{
  "mcpServers": {
    "invoice-validator": {
      "url": "https://invoice-payment-id-validator.p.rapidapi.com/mcp",
      "headers": {
        "X-RapidAPI-Key": "YOUR_RAPIDAPI_KEY",
        "X-RapidAPI-Host": "invoice-payment-id-validator.p.rapidapi.com"
      }
    }
  }
}
```

For clients that only support stdio: `npx -y mcp-remote https://invoice-validator.mohamed-bahaa53000.workers.dev/demo/mcp`

## Notes

- Stateless. Inputs aren't stored beyond standard request logs.
- Validation checks format and checksums (plus VIES when `live=true`). It doesn't prove an account belongs to a given company.