Product December 5, 2025 6 min read

How InvoStaq's Traffic Light Protocol Works

Every invoice gets a simple red, amber, or green signal — so you know instantly whether it's compliant, needs review, or must be blocked. Here's how it works under the hood.

InvoStaq Product Team

Product engineering & design

InvoStaq's Traffic Light Protocol (TLP) is our real-time compliance scoring system. Every invoice that passes through InvoStaq gets an instant red, amber, or green signal based on 400+ validation rules, AI anomaly detection, and jurisdiction-specific compliance checks.

Think of it as an airport security scanner for your invoices — but instead of checking for prohibited items, it checks for compliance issues, data errors, and potential fraud. And it does it in under 200 milliseconds.

< 200ms

Validation speed

400+

Compliance rules

99.7%

Detection accuracy

3

Clear signal types

How It Works

When an invoice enters InvoStaq — whether from your ERP, a Peppol network, or a manual upload — it immediately enters the TLP pipeline. The system runs a multi-stage analysis and assigns one of three signals:

The Three Signals

!🔴 BLOCKCritical error — invoice rejected outright🟡 WARNPotential issue — flagged for review🟢 PASSFully compliant — cleared for submissionMissing tax ID, wrong schemaAction: Auto-fix or return to senderUnusual amount, new supplierAction: Escalate for human reviewAll 400+ rules validatedAction: Auto-submit to authority

GREEN — Pass

The invoice passes all validation checks. It's structurally correct, tax calculations are accurate, all mandatory fields are present, and no anomalies were detected. The invoice is automatically cleared for submission to the tax authority.

Action: Auto-submit to authority, archive, and notify sender of success.

AMBER — Warn

The invoice is technically valid but something looks unusual. This could be an unusually high amount, a new supplier, a slight discrepancy with purchase order data, or a field that passes validation but might be incorrect.

Action: Escalate to designated reviewer, provide AI explanation, hold until approved or rejected.

RED — Block

The invoice has one or more critical compliance failures. Missing mandatory fields, invalid tax calculations, wrong schema format, or detected fraud indicators. The invoice cannot be submitted in its current state.

Action: Block submission, generate detailed error report, attempt auto-fix where possible, notify sender with correction guidance.

Validation Pipeline

The TLP score is determined by a multi-stage pipeline that processes every invoice in sequence:

Invoice InAny formatSchema CheckStructureBusiness Rules400+ rulesAI AnomalyML patternsTLP Score🔴🟡🟢
1
Stage 1: Schema Validation

Checks the invoice against the target standard (EN16931, Peppol PINT, ZATCA). Validates XML structure, namespaces, required elements, and data types.

2
Stage 2: Business Rule Engine

Applies 400+ country-specific rules: tax rate verification, mandatory field checks, cross-reference validation, currency validation, date logic.

3
Stage 3: AI Anomaly Detection

Machine learning models trained on millions of invoices detect patterns that indicate errors, fraud, or unusual activity — even if technically valid.

4
Stage 4: TLP Score Assignment

Based on the results of all three stages, the invoice receives its final TLP signal. Green = all clear, Amber = needs review, Red = blocked.

Real Examples

🟢 GREENStandard B2B Invoice

A Peppol PINT invoice from a known supplier, correct VAT at 21%, all mandatory fields present, amount within normal range.

Result: Auto-cleared and submitted to Belgian tax authority in 180ms.
🟡 AMBERUnusually High Amount

Structurally valid invoice from an existing supplier, but the amount is 5× their typical invoice value and references a new project code.

Result: Flagged for finance team review with AI explanation: 'Amount significantly above supplier average.'
🔴 REDMissing Tax Registration

Invoice with correct format but the seller's VAT registration number is empty — a mandatory field for ZATCA compliance.

Result: Blocked. Auto-generated correction request sent to supplier with specific field guidance.

Your Dashboard

The InvoStaq dashboard gives you real-time visibility into your TLP metrics. At a glance, see your compliance rate, pending reviews, blocked invoices, and trend data. Every signal links to a detailed audit trail so you can drill into any invoice's validation history.

94.2%

Green (Passed)

4.1%

Amber (Review)

1.7%

Red (Blocked)

See TLP in Action

Watch the Traffic Light Protocol validate your invoices in real-time. Book a live demo today.