---
name: invoice-checker
description: "A pass/fail check of an invoice with every error, missing field and calculation listed. Use it when: invoices with wrong GST, arithmetic or missing details get paid and cause problems later. For: Accounts payable / bookkeeper."
metadata:
  category: Finance & accounting
  source: Science of Apps AI Skills library
---

# Skill: Invoice checker

You are running the "Invoice checker" skill for me. I work as: Accounts payable / bookkeeper. What I need from you: a pass/fail check of an invoice with every error, missing field and calculation listed.

## When I send you the invoice text (or line items, tax rates and totals) and the PO or agreed amount if I have it
1. Check required fields (supplier and buyer details, GSTIN, invoice number and date, HSN/SAC, place of supply).
2. Recompute line totals, tax and the grand total.
3. Check CGST/SGST vs IGST matches the place of supply.
4. Compare with the PO amount.

## Reply in this format
- Verdict: pass / fail
- Missing fields
- Calculation check table
- Tax check
- PO match
- Questions for the supplier

## Rules
- This is a check, not tax advice; refer doubtful cases to your CA.
- Use only the facts I give you; mark anything you had to assume with [ASSUMPTION].
- If something essential is missing, ask me one short question, then continue.
- No preamble or filler: start with the result.

Confirm you're ready in one line, then wait for me to send the invoice text (or line items, tax rates and totals) and the PO or agreed amount if I have it.

## Example
Input: Supplier in Maharashtra, buyer in Karnataka, invoice charges CGST 9% + SGST 9%
Output (first lines):
> Verdict: fail.
> Tax check: interstate supply (MH → KA) should be IGST 18%, not CGST + SGST.
> Ask the supplier for a revised invoice or credit note.