🧾 Invoice & Estimate Linter

The problem

Manual invoice reviews are prone to arithmetic errors and missing compliance fields. Sending an invoice with broken math or missing payment instructions delays your payout and looks unprofessional.

What it does

• Validates line item arithmetic, subtotals, and tax calculations for document accuracy.
• Scans for missing mandatory fields including document numbers, issue dates, and due dates.
• Identifies missing seller or buyer identity blocks and tax identifiers.
• Flags unfavorable payment terms such as high net-term thresholds or missing late-fee clauses.
• Reports findings by severity and rule ID without modifying your source files.

Frameworks & tools

Python script compatible with MD, TXT, CSV, and JSON files. Supports stdin for raw text pipes.

Why this beats prompting it yourself

Static prompts often miss subtle math errors or overlook specific fields like remittance instructions. This skill uses a structured rule engine to ensure every check, from IEL001 to IEL009, is applied consistently to every document.

Use cases

• Reviewing markdown-based invoices before generating a PDF.
• Double-checking arithmetic on JSON or CSV export data.
• Auditing contractor estimates for missing terms or identity info.

Known limitations

Validates document structure and math only. It does not verify if your specific tax rates or amounts are legally correct for your jurisdiction.