invoice-generator

name	invoice-generator
description	Generate professional PDF invoices from line items with customizable templates, tax calculations, and branding. Supports batch generation from CSV.

Invoice Generator

Create professional PDF invoices with customizable templates, automatic tax calculations, and company branding. Perfect for freelancers, small businesses, and automated billing systems.

Quick Start

from scripts.invoice_gen import InvoiceGenerator

# Create a simple invoice
invoice = InvoiceGenerator()
invoice.set_company("Acme Corp", "123 Business St, City, ST 12345")
invoice.set_client("John Smith", "456 Client Ave, Town, ST 67890")
invoice.add_item("Consulting Services", 8, 150.00)
invoice.add_item("Software License", 1, 500.00)
invoice.generate().save("invoice_001.pdf")

# From dictionary
data = {
    'invoice_number': 'INV-2024-001',
    'company': {'name': 'My Company', 'address': '123 Main St'},
    'client': {'name': 'Client Inc', 'address': '456 Oak Ave'},
    'items': [
        {'description': 'Web Design', 'quantity': 1, 'rate': 2500},
        {'description': 'Hosting (Annual)', 'quantity': 1, 'rate': 300}
    ]
}
invoice = InvoiceGenerator.from_dict(data)
invoice.generate().save("invoice.pdf")

Features

• Professional Templates: Clean, modern invoice designs
• Custom Branding: Logo, colors, fonts
• Tax Calculations: Multiple tax rates, compound taxes
• Discounts: Percentage or fixed amount discounts
• Payment Terms: Due dates, payment instructions, bank details
• Multi-Currency: Support for various currency symbols
• Batch Generation: Create multiple invoices from CSV
• Export: PDF output with optional preview

API Reference

Initialization

invoice = InvoiceGenerator()

# From dictionary
invoice = InvoiceGenerator.from_dict(data)

# From CSV (batch)
invoices = InvoiceGenerator.from_csv("invoices.csv")

Company Information

# Basic company info
invoice.set_company(
    name="Acme Corporation",
    address="123 Business Street\nCity, State 12345"
)

# Full company details
invoice.set_company(
    name="Acme Corporation",
    address="123 Business Street\nCity, State 12345",
    email="[e-mail]",
    phone="[phone]",
    website="www.acme.com",
    tax_id="12-3456789"
)

# Add logo
invoice.set_logo("logo.png")
invoice.set_logo("logo.png", width=150)  # Specify width in pixels

Client Information

# Basic client info
invoice.set_client(
    name="John Smith",
    address="456 Client Avenue\nTown, State 67890"
)

# Full client details
invoice.set_client(
    name="John Smith",
    company="Smith Enterprises",
    address="456 Client Avenue\nTown, State 67890",
    email="[e-mail]"
)

Invoice Details

# Invoice number and dates
invoice.set_invoice_number("INV-2024-001")
invoice.set_date("2024-01-15")  # Invoice date
invoice.set_due_date("2024-02-14")  # Due date

# Or use days from invoice date
invoice.set_due_days(30)  # Due in 30 days

# Currency
invoice.set_currency("USD")  # $
invoice.set_currency("EUR")  # €
invoice.set_currency("GBP")  # £
invoice.set_currency("$", symbol_only=True)  # Custom symbol

Line Items

# Add items
invoice.add_item(
    description="Consulting Services",
    quantity=8,
    rate=150.00
)

# With unit
invoice.add_item("Development", 40, 125.00, unit="hours")

# With item-level discount
invoice.add_item("Product", 10, 50.00, discount=10)  # 10% discount

# From list
items = [
    {"description": "Item 1", "quantity": 2, "rate": 100},
    {"description": "Item 2", "quantity": 1, "rate": 250}
]
invoice.add_items(items)

Taxes and Discounts

# Add tax
invoice.add_tax("Sales Tax", 8.25)  # 8.25%
invoice.add_tax("State Tax", 5.0)

# Compound tax (applied after other taxes)
invoice.add_tax("GST", 10.0, compound=True)

# Discount on subtotal
invoice.set_discount(10)  # 10% off
invoice.set_discount(50, is_percentage=False)  # $50 off

Payment Information

# Payment terms
invoice.set_payment_terms("Net 30")

# Payment instructions
invoice.set_payment_instructions("""
Payment Methods:
- Bank Transfer: Account #12345, Routing #67890
- PayPal: [e-mail]
- Check payable to: Acme Corporation
""")

# Bank details
invoice.set_bank_details(
    bank_name="First National Bank",
    account_name="Acme Corporation",
    account_number="1234567890",
    routing_number="987654321",
    swift_code="FNBKUS12"
)

Notes and Terms

# Notes (appears on invoice)
invoice.set_notes("Thank you for your business!")

# Terms and conditions
invoice.set_terms("""
1. Payment due within 30 days
2. Late payments subject to 1.5% monthly interest
3. All sales are final
""")

Styling

# Color theme
invoice.set_colors(
    primary="#2563eb",    # Headers, accent
    secondary="#64748b",  # Secondary text
    background="#f8fafc"  # Background
)

# Template style
invoice.set_template("modern")    # Default
invoice.set_template("classic")   # Traditional look
invoice.set_template("minimal")   # Clean, minimal

# Font
invoice.set_font("Helvetica")  # Default
invoice.set_font("Times")

Generation and Export

# Generate invoice
invoice.generate()

# Save to PDF
invoice.save("invoice.pdf")

# Save with custom filename pattern
invoice.save_as("INV-{number}-{client}.pdf")

# Get PDF bytes (for email attachment, etc.)
pdf_bytes = invoice.to_bytes()

Data Formats

Dictionary Format

data = {
    'invoice_number': 'INV-2024-001',
    'date': '2024-01-15',
    'due_date': '2024-02-14',
    'currency': 'USD',

    'company': {
        'name': 'Acme Corporation',
        'address': '123 Business St\nCity, ST 12345',
        'email': '[e-mail]',
        'phone': '[phone]',
        'logo': 'logo.png'  # Optional
    },

    'client': {
        'name': 'John Smith',
        'company': 'Smith Enterprises',
        'address': '456 Client Ave\nTown, ST 67890',
        'email': '[e-mail]'
    },

    'items': [
        {'description': 'Consulting', 'quantity': 8, 'rate': 150, 'unit': 'hours'},
        {'description': 'Software License', 'quantity': 1, 'rate': 500}
    ],

    'taxes': [
        {'name': 'Sales Tax', 'rate': 8.25}
    ],

    'discount': ,  
    : ,
    : 
}

CSV Format for Batch

invoice_number,date,due_date,client_name,client_address,item_description,quantity,rate,tax_rate
INV-001,2024-01-15,2024-02-14,John Smith,123 Main St,Consulting,8,150,8.25
INV-001,2024-01-15,2024-02-14,John Smith,123 Main St,Software,1,500,8.25
INV-002,2024-01-16,2024-02-15,Jane Doe,456 Oak Ave,Design,1,2000,8.25

CLI Usage

# Generate from JSON
python invoice_gen.py --input invoice.json --output invoice.pdf

# Batch from CSV
python invoice_gen.py --batch invoices.csv --output-dir ./invoices/

# Quick invoice
python invoice_gen.py --quick \
    --company "My Company" \
    --client "Client Name" \
    --items "Service,1,500;Product,2,100" \
    --output invoice.pdf

# With options
python invoice_gen.py --input data.json \
    --template modern \
    --currency EUR \
    --output invoice.pdf

CLI Arguments

Argument	Description	Default
--input	Input JSON file	-
--batch	Batch CSV file	-
--output	Output PDF path	invoice.pdf
--output-dir	Output directory (batch)	./
--template	Template style	modern
--currency	Currency code	USD
--logo	Logo image path	-
--quick	Quick mode with inline data	-

Examples

Freelancer Invoice

invoice = InvoiceGenerator()

invoice.set_company(
    name="Jane Developer",
    address="123 Freelance Lane\nRemote, WFH 00000",
    email="[e-mail]"
)

invoice.set_client(
    name="Startup Inc",
    address="456 Venture Blvd\nSilicon Valley, CA 94000"
)

invoice.set_invoice_number("2024-001")
invoice.add_item("Frontend Development", 40, 125, unit="hours")
invoice.add_item("Backend Development", 32, 150, unit="hours")
invoice.add_item("Code Review", 8, 100, unit="hours")

invoice.set_payment_terms("Net 15")
invoice.set_notes("Thank you for the opportunity!")

invoice.generate().save("freelance_invoice.pdf")

Business Invoice with Taxes

invoice = InvoiceGenerator()

invoice.set_company("Acme Corp", "123 Business St, City, ST 12345")
invoice.set_logo("acme_logo.png")
invoice.set_client("Big Client LLC", "456 Corporate Ave, Metro, ST 67890")

invoice.add_item("Enterprise License", 1, 5000)
invoice.add_item("Implementation", 20, 200, unit="hours")
invoice.add_item("Training", 2, 500, unit="sessions")
invoice.add_item("Support (Annual)", 1, 1200)

invoice.add_tax("State Tax", 6.0)
invoice.add_tax("County Tax", 2.25)

invoice.set_discount(5)  # 5% volume discount

invoice.set_bank_details(
    bank_name="Business Bank",
    account_number="9876543210",
    routing_number="123456789"
)

invoice.generate().save("business_invoice.pdf")

Batch Invoice Generation

# From CSV
invoices = InvoiceGenerator.from_csv("monthly_invoices.csv")

for inv in invoices:
    inv.set_company("My Company", "123 Main St")
    inv.set_logo("logo.png")
    inv.generate()
    inv.save(f"invoices/{inv.invoice_number}.pdf")

# Or with batch save
InvoiceGenerator.batch_generate(
    "invoices.csv",
    output_dir="./invoices/",
    company_name="My Company",
    company_address="123 Main St",
    logo="logo.png"
)

Dependencies

reportlab>=4.0.0
Pillow>=10.0.0

Limitations

• Logo images should be PNG or JPEG
• Maximum ~50 line items per page (auto-pagination for more)
• PDF only (no HTML or DOCX export)
• Single currency per invoice