SKILL.md

Invoice Template Skill

Name: invoice-template
Author: claude-office-skills

Overview

This skill generates professional PDF invoices from structured data and templates. Create invoices with company branding, itemized lists, tax calculations, and payment details.

How to Use

Describe what you want to accomplish

Provide any required input data or files

I'll execute the appropriate operations

Example prompts:

"Generate invoices from order data"

"Create recurring invoices"

"Batch generate monthly invoices"

"Customize invoice templates per client"

Domain Knowledge

Invoice Data Structure

invoice_data = {

    "invoice_number": "INV-2026-001",

    "date": "2026-01-30",

    "due_date": "2026-02-28",

    "from": {

        "name": "Your Company",

        "address": "123 Business St",

        "email": "billing@company.com"

    },

    "to": {

        "name": "Client Name",

        "address": "456 Client Ave",

        "email": "client@example.com"

    },

    "items": [

        {"description": "Consulting", "quantity": 10, "rate": 150.00},

        {"description": "Development", "quantity": 20, "rate": 100.00}

    ],

    "tax_rate": 0.08,

    "notes": "Payment due within 30 days"

}

PDF Generation with ReportLab

from reportlab.lib.pagesizes import letter

from reportlab.pdfgen import canvas

from reportlab.lib.units import inch

def create_invoice(data: dict, output_path: str):

    c = canvas.Canvas(output_path, pagesize=letter)

    width, height = letter

    # Header

    c.setFont("Helvetica-Bold", 24)

    c.drawString(1*inch, height - 1*inch, "INVOICE")

    # Invoice details

    c.setFont("Helvetica", 12)

    c.drawString(1*inch, height - 1.5*inch, f"Invoice #: {data['invoice_number']}")

    c.drawString(1*inch, height - 1.75*inch, f"Date: {data['date']}")

    # From/To

    y = height - 2.5*inch

    c.drawString(1*inch, y, f"From: {data['from']['name']}")

    c.drawString(4*inch, y, f"To: {data['to']['name']}")

    # Items table

    y = height - 4*inch

    c.setFont("Helvetica-Bold", 10)

    c.drawString(1*inch, y, "Description")

    c.drawString(4*inch, y, "Qty")

    c.drawString(5*inch, y, "Rate")

    c.drawString(6*inch, y, "Amount")

    c.setFont("Helvetica", 10)

    subtotal = 0

    for item in data['items']:

        y -= 0.3*inch

        amount = item['quantity'] * item['rate']

        subtotal += amount

        c.drawString(1*inch, y, item['description'])

        c.drawString(4*inch, y, str(item['quantity']))

        c.drawString(5*inch, y, f"${item['rate']:.2f}")

        c.drawString(6*inch, y, f"${amount:.2f}")

    # Totals

    tax = subtotal * data['tax_rate']

    total = subtotal + tax

    y -= 0.5*inch

    c.drawString(5*inch, y, f"Subtotal: ${subtotal:.2f}")

    y -= 0.25*inch

    c.drawString(5*inch, y, f"Tax ({data['tax_rate']*100}%): ${tax:.2f}")

    y -= 0.25*inch

    c.setFont("Helvetica-Bold", 12)

    c.drawString(5*inch, y, f"Total: ${total:.2f}")

    c.save()

    return output_path

HTML Template Approach

from weasyprint import HTML

from jinja2 import Template

invoice_template = """

<!DOCTYPE html>

<html>

<head>

    <style>

        body { font-family: Arial; margin: 40px; }

        .header { display: flex; justify-content: space-between; }

        table { width: 100%; border-collapse: collapse; margin: 20px 0; }

        th, td { border: 1px solid #ddd; padding: 10px; text-align: left; }

        .total { font-weight: bold; font-size: 18px; }

    </style>

</head>

<body>

    <div class="header">

        <h1>INVOICE</h1>

        <div>

            <p>Invoice #: {{ invoice_number }}</p>

            <p>Date: {{ date }}</p>

        </div>

    </div>

    <table>

        <tr><th>Description</th><th>Qty</th><th>Rate</th><th>Amount</th></tr>

        {% for item in items %}

        <tr>

            <td>{{ item.description }}</td>

            <td>{{ item.quantity }}</td>

            <td>${{ "%.2f"|format(item.rate) }}</td>

            <td>${{ "%.2f"|format(item.quantity * item.rate) }}</td>

        </tr>

        {% endfor %}

    </table>

    <p class="total">Total: ${{ "%.2f"|format(total) }}</p>

</body>

</html>

"""

def create_invoice_html(data: dict, output_path: str):

    template = Template(invoice_template)

    # Calculate total

    total = sum(i['quantity'] * i['rate'] for i in data['items'])

    total *= (1 + data.get('tax_rate', 0))

    data['total'] = total

    html = template.render(**data)

    HTML(string=html).write_pdf(output_path)

    return output_path

Best Practices

Validate required fields before generation

Use templates for consistent branding

Auto-calculate totals (don't trust input)

Include payment instructions and terms

Installation

# Install required dependencies

pip install python-docx openpyxl python-pptx reportlab jinja2

Resources

easy-invoice-pdf Repository

Claude Office Skills Hub

invoice-template