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
- Discovery — Identify client, service, amount. Load or create client record.
- Draft — Generate invoice with auto-calculated taxes and next number.
- Review — Show preview, allow edits.
- Finalize — Generate PDF, lock number.
- Send — Email to client (optional).
- 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)