Invoice Generator

Overview

This project automates invoice creation and delivery for freelancers and small teams. Instead of manually formatting invoices, exporting PDFs, and sending emails, the workflow generates a branded invoice PDF from structured data, emails it to the client, and logs everything in a tracker for follow-up and bookkeeping.

Problem

Manual invoicing is repetitive and error-prone:

Copying values into templates leads to mistakes
PDFs are generated inconsistently across clients
Tracking sent, paid, and overdue invoices becomes messy
Follow-ups are often missed

Solution

A workflow that turns structured invoice inputs into a complete invoice lifecycle:

Collect invoice fields (client, line items, taxes, due date)
Generate a PDF invoice using PDFMonkey
Send the invoice automatically via Gmail SMTP
Store the PDF + metadata in Airtable
Optionally store files in Google Drive for centralized access

Architecture

Flow

Trigger: new invoice request (Form / Airtable / webhook)
Validate + normalize invoice data (totals, currency, taxes)
PDF generation (PDFMonkey template) → returns PDF URL
Email delivery (Gmail SMTP) with PDF attached or linked
Storage:
- Airtable record (status, invoice number, client, due date)
- Attachment stored via public URL
- Optional Google Drive upload + link saved back to Airtable

Key design choices

Template-driven PDF generation for consistent branding
Central tracking table so you always know invoice status
Modular design so it can be reused for payment reminders

Tech Stack

n8n (workflow orchestration)
PDFMonkey (PDF generation template)
Gmail SMTP (invoice delivery)
Airtable (invoice tracker)
Google Drive (optional storage)

Results

Faster invoice turnaround (generate + send in minutes)
Fewer manual errors through structured inputs
Clear tracking of invoices (sent, paid, overdue) in one place

What’s next

Overdue payment reminder automation
Payment status updates via Stripe/PayPal webhooks
Lightweight client portal or frontend UI