Create a recurring invoice generator

Creating a recurring invoice generator can be approached in multiple ways depending on the technology stack and environment you want to use. Below is a simplified example of how to create a basic recurring invoice generator using Python. This script will generate invoices on a recurring schedule, such as monthly, and save them as PDF files.

Recurring Invoice Generator (Python Example)

This example will:

• Define invoice data

• Generate an invoice PDF

• Schedule recurring invoice creation (e.g., every month)

python
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from fpdf import FPDF
import datetime
import os
import schedule
import time

class InvoiceGenerator:
    def __init__(self, client_name, client_address, items, invoice_number, invoice_date):
        self.client_name = client_name
        self.client_address = client_address
        self.items = items  # list of tuples (description, quantity, price)
        self.invoice_number = invoice_number
        self.invoice_date = invoice_date
        self.pdf = FPDF()

    def generate_pdf(self):
        self.pdf.add_page()
        self.pdf.set_font("Arial", size=12)

        # Header
        self.pdf.cell(200, 10, txt="Invoice", ln=True, align="C")

        # Invoice Info
        self.pdf.cell(100, 10, f"Invoice Number: {self.invoice_number}", ln=True)
        self.pdf.cell(100, 10, f"Invoice Date: {self.invoice_date.strftime('%Y-%m-%d')}", ln=True)

        # Client Info
        self.pdf.cell(100, 10, f"Billed To: {self.client_name}", ln=True)
        self.pdf.multi_cell(0, 10, f"Address: {self.client_address}")

        self.pdf.ln(10)

        # Table Header
        self.pdf.cell(80, 10, "Description", 1)
        self.pdf.cell(30, 10, "Quantity", 1)
        self.pdf.cell(40, 10, "Unit Price", 1)
        self.pdf.cell(40, 10, "Total", 1, ln=True)

        # Table Rows
        total_amount = 0
        for desc, qty, price in self.items:
            total = qty * price
            total_amount += total
            self.pdf.cell(80, 10, desc, 1)
            self.pdf.cell(30, 10, str(qty), 1)
            self.pdf.cell(40, 10, f"${price:.2f}", 1)
            self.pdf.cell(40, 10, f"${total:.2f}", 1, ln=True)

        self.pdf.ln(10)
        self.pdf.cell(150, 10, "Total Amount", 1)
        self.pdf.cell(40, 10, f"${total_amount:.2f}", 1, ln=True)

        # Save PDF
        file_name = f"invoice_{self.invoice_number}.pdf"
        self.pdf.output(file_name)
        print(f"Invoice {file_name} generated successfully.")

def create_invoice():
    today = datetime.date.today()
    invoice_number = today.strftime("%Y%m")  # e.g. 202505 for May 2025

    # Example invoice data - in real case, fetch from DB or input
    client_name = "John Doe"
    client_address = "123 Main StreetnCityvillenCountry"
    items = [
        ("Website Design", 1, 500.00),
        ("Hosting (1 year)", 1, 100.00),
        ("Maintenance", 12, 25.00)
    ]

    invoice = InvoiceGenerator(client_name, client_address, items, invoice_number, today)
    invoice.generate_pdf()

# Schedule to run once every month
schedule.every(30).days.do(create_invoice)

print("Recurring invoice generator started. Waiting to generate invoices...")

while True:
    schedule.run_pending()
    time.sleep(1)

How This Works

• The script uses fpdf library to create PDFs.

• InvoiceGenerator class formats invoice content and saves it as a PDF.

• The create_invoice function generates a new invoice using preset data and saves it.

• The script schedules this function to run every 30 days using the schedule module.

• You can modify the scheduling logic for exact dates or intervals.

Requirements

Install dependencies before running:

bash
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pip install fpdf schedule

This is a minimal example and can be expanded with:

• Dynamic invoice numbers stored in a database

• Fetching client data and invoice items from external sources

• Emailing generated invoices automatically

• More sophisticated scheduling (e.g., monthly on the 1st day)

If you want me to build this for a web framework (like Django, Flask, Node.js) or a specific platform, just let me know!