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

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)