Connor Worth - Invoicing Software

The Problem

Within my business, Coast Tutoring, the use of accounting software such as MYOB has been an integral part of managing invoicing and payroll across all aspects of operations. For over 18 months, I benefited from this service at no cost, which significantly streamlined administrative tasks without impacting my bottom line. However, recent price increases have transformed this once-free service into a notable expense, now exceeding $60 per month. As someone who strives for efficiency and sustainability in business decisions, I find myself grappling with the value of this investment. Given that I only utilise a fraction of the software's capabilities, this recurring expense feels increasingly unjustifiable. It has become clear that a change is necessary—whether by seeking a more cost-effective alternative, renegotiating terms, or re-evaluating my reliance on such external tools altogether.

Idea

The concept arose from the need to tackle inefficiencies and mounting costs in my current invoicing system, while retaining the simplicity for both me, the user, and customers. I began by examining the fundamental requirements of the process: retrieving customer data, generating invoices, and maintaining accurate records.

Realising that much of this could be streamlined, I considered the resources already at my disposal, such as Python for automation and Excel for data storage. This prompted a structured brainstorming process, during which I outlined how each stage—filtering data by invoice number, generating PDF invoices, and organising outputs—could be automated.

I also identified potential edge cases in invoicing, such as incorporating due date tracking and accommodating multi-line invoices.

By focusing on these essentials, I conceptualised a tailored solution that would eliminate unnecessary features while meeting the specific operational needs of my business, allowing me to create an MVP.

Solution

The resulting Python code shown below loads customer data from a local Excel file, also used as a record of invoicing, asks user for invoice number before creating a PDF invoice and saving to the specified local folder.

import pandas as pd

from fpdf import FPDF

import datetime

# datetime object containing current date and time

now = datetime.datetime.now()

dt_now = now.strftime("%d/%m/%Y")

dt_due_long = now + datetime.timedelta(days=14)

dt_due = dt_due_long.strftime("%d/%m/%Y")

print(dt_due)

def import_customer_data(file_path, invoice_number):

"""Imports customer data from an Excel file filtered by invoice number."""

try:

data = pd.read_excel(file_path)

# Debug: Print data and types

print("Loaded data:")

print(data.head())

print("Invoice Number column type:", data['Invoice Number'].dtype)

# Ensure invoice number comparison works correctly

if data['Invoice Number'].dtype != type(invoice_number):

invoice_number = str(invoice_number) if data['Invoice Number'].dtype == object else int(invoice_number)

filtered_data = data[data['Invoice Number'] == invoice_number]

if filtered_data.empty:

print(f"No data found for Invoice Number: {invoice_number}")

return None

return filtered_data

except Exception as e:

print(f"Error importing data: {e}")

return None

def generate_invoice(customer_data, output_path):

"""Generates a PDF invoice for the provided customer data."""

try:

pdf = FPDF()

pdf.add_page()

pdf.set_font("Arial", size=12)

# Add Logo

pdf.image(r"D:\Users\conno\OneDrive\Desktop\Coast Tutoring\Website\Coast_Tutoring_Logo.png", x=10, y=8, w=30)

# Add header

pdf.ln(5)

pdf.set_font("Arial", style='B', size=14)

pdf.cell(0, 10, txt="Coast Tutoring Invoice", ln=True, align="C")

pdf.ln(25)

# Add invoice number and date

invoice_number = customer_data['Invoice Number'].iloc[0]

pdf.set_font("Arial", style= 'B', size=11)

pdf.cell(0, 5, txt=f"Invoice Number: {invoice_number}", ln=True, align="L")

pdf.set_font("Arial", size=11)

pdf.cell(0, 10, txt=f"Issue Date: {dt_now}", ln=False, align="L")

pdf.cell(0, 10, txt=f"Due Date: {dt_due}", ln=True, align="R")

# Add customer details

customer_name = customer_data['Customer Name'].iloc[0]

#customer_address = customer_data['Customer Address'].iloc[0]

pdf.cell(0, 5, txt=f"Name: {customer_name}", ln=True, align="L")

#pdf.cell(0, 5, txt=f"Address: {customer_address}", ln=True, align="L")

# Add line break

pdf.ln(10)

# Add table header

pdf.set_font("Arial", style='B', size=11)

pdf.cell(100, 10, txt="Description", border=1, align='C')

pdf.cell(30, 10, txt="Quantity", border=1, align='C')

pdf.cell(30, 10, txt="Unit Cost", border=1, align='C')

pdf.cell(30, 10, txt="Subtotal", border=1, align='C')

pdf.ln(10)

# Add table rows for all items in the invoice

pdf.set_font("Arial", size=11)

total = 0

for _, row in customer_data.iterrows():

description = row['Description']

quantity = row['Quantity']

unit_cost = row['Unit Cost']

subtotal = row['Total']

total += subtotal

pdf.cell(100, 10, txt=f"{description}", border=1, align='L')

pdf.cell(30, 10, txt=f"{quantity}", border=1, align='C')

pdf.cell(30, 10, txt=f"${unit_cost:.2f}", border=1, align='C')

pdf.cell(30, 10, txt=f"${subtotal:.2f}", border=1, align='R')

pdf.ln(10)

# Add total

pdf.set_font("Arial", style='B', size=11)

pdf.cell(160, 10, txt="Total", border=1, align='R')

pdf.cell(30, 10, txt=f"${total:.2f}", border=1, align='R')

pdf.ln(10)

# Payment instructions

pdf.ln(10)

pdf.set_font("Arial", style='B', size=11)

pdf.cell(0, 10, txt=f"Due Date: {dt_due}", ln=True, align="L")

pdf.ln(5)

pdf.set_font("Arial", style='B', size=12)

pdf.cell(0, 10, txt="Payment Instructions", ln=True, align="L")

pdf.cell(0, 10, txt="Bank deposit via EFT", ln=True, align="L")

pdf.set_font("Arial", size=11)

pdf.cell(0, 6, txt="Bank: NAB", ln=True, align="L")

pdf.cell(0, 6, txt="Name: COAST TUTORING", ln=True, align="L")

pdf.cell(0, 6, txt="BSB: 082356", ln=True, align="L")

pdf.cell(0, 6, txt="AC#: 355918718", ln=True, align="L")

pdf.cell(0, 6, txt=f"Ref#: {invoice_number} ", ln=True, align="L")

# Customer Help

pdf.ln(20)

pdf.set_font("Arial", style='B', size=12)

pdf.cell(0, 10, txt="Need Help?", ln=True, align="L")

pdf.set_font("Arial", size=11)

pdf.cell(0, 6, txt="If you have any questions about this invoice, please contact: connor@coasttutoring.net or 0481 679 212", ln=True, align="L")

# Add footer

pdf.set_y(-40)

pdf.set_font("Arial", style='I', size=8)

pdf.cell(0, 10, txt=f"Thank you for your business {customer_name}!", align='C')

pdf.ln(5)

pdf.cell(0, 10, txt=f"Issue Date: {dt_now}", ln=False, align="L")

pdf.cell(-195, 10, txt="Coast Tutoring", align='C')

pdf.cell(0, 10, txt="ABN: 123456789", align='R')

pdf.ln(-5)

# Save the invoice as a PDF

customer_file = f"{output_path}/Coast_Tutoring_Invoice_{invoice_number}_{customer_name.replace(' ', '_')}.pdf"

pdf.output(customer_file)

print(f"Invoice generated for {customer_name} at {customer_file}")

except Exception as e:

print(f"Error generating invoice: {e}")

if __name__ == "__main__":

# Specify the Excel file path and output directory

#excel_file_path = r"C:\Users\conno\OneDrive\Desktop\Coast Tutoring\Clients\Invoices\InvoiceData\InvoiceDataFile.xlsx"

excel_file_path = r"D:\Users\conno\OneDrive\Desktop\Coast Tutoring\Clients\Invoices\InvoiceData\InvoiceDataFile.xlsx"

#output_directory = r"C:\Users\conno\OneDrive\Desktop\Coast Tutoring\Clients\Invoices\InvoiceData"

output_directory = r"D:\Users\conno\OneDrive\Desktop\Coast Tutoring\Clients\Invoices\2025"

# Prompt user for invoice number

invoice_number = input("Enter the Invoice Number: ")

# Import data

customer_data = import_customer_data(excel_file_path, invoice_number)

if customer_data is not None:

# Generate invoices

generate_invoice(customer_data, output_directory)

Below is the PDF export for an example of a single line invoice and a multi-line invoice.

Single Line Invoice

Multiple Line Invoice

For the Future

The future development of this program envisions the creation of a web application, designed to function similarly to the MYOB platform previously utilised. This advancement would enable the majority of the Python code already written to remain a core component of the backend infrastructure, ensuring continuity and leveraging the work already completed.

Key changes required for this transition would include the development of a dynamic table within the web app for inputting and managing data, replacing the reliance on local Excel files. Additionally, features such as invoice due date tracking and the ability to download invoices directly through the web interface—rather than saving them to a local folder—would need to be implemented. These upgrades aim to enhance the program’s accessibility, functionality, and efficiency, ultimately offering a more streamlined and user-friendly experience for both myself and any potential collaborators.