# Invoice

> Create and send professional invoices with automatic numbering, tax calculation, templates, and payment tracking.

- Skill: `modbender/invoice` (Agent Skill, multi-file: 14 files)
- Install (CLI): `npx skillmds@latest add modbender/invoice`
- Raw SKILL.md: https://api.skillmd.com/api/skills/modbender/invoice/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Finance & Business
- Author: modbender (https://skillmd.com/u/modbender)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/modbender/invoice

---


## Role

Create invoices through a structured process. Gather client data, calculate taxes, generate PDF, send, track payment.

**Key difference:** This skill CREATES invoices to send. The `invoices` skill MANAGES received invoices.

---

## Storage

```
~/billing/
├── drafts/                   # Work in progress
│   └── {client-name}/
│       ├── current.md        # Latest version
│       └── versions/         # v001.md, v002.md
├── sent/                     # Finalized invoices
│   └── 2026/
│       └── F-2026-001.pdf
├── clients/                  # Client database
│   └── index.json
├── config.json               # User's business data, templates
└── series.json               # Numbering per series
```

---

## Quick Reference

| Topic | File |
|-------|------|
| Invoice creation phases | `phases.md` |
| Client data management | `clients.md` |
| Template and PDF generation | `templates.md` |
| Legal requirements by country | `legal.md` |
| Invoice types (regular, simplified, credit) | `types.md` |

---

## Process Summary

1. **Discovery** — Identify client, service, amount. Load or create client record.
2. **Draft** — Generate invoice with auto-calculated taxes and next number.
3. **Review** — Show preview, allow edits.
4. **Finalize** — Generate PDF, lock number.
5. **Send** — Email to client (optional).
6. **Track** — Monitor payment status.

See `phases.md` for detailed workflow.

---

## Critical Rules

- **Never reuse numbers** — Even cancelled invoices keep their number. Use credit notes for corrections.
- **Correlative numbering** — No gaps within a series. F-001, F-002, F-003.
- **Tax calculation** — Always show: base, rate, amount, total. Never hide taxes.
- **Client data required** — For B2B: company name, tax ID, address. No invoice without complete data.

---

## Configuration Required

Before first invoice, collect:
- User's business name, tax ID, address
- Bank details (IBAN) for payment
- Default tax rate
- Invoice series format (e.g., "F-2026-")
- Email for sending (optional)