Built an end-to-end invoicing automation for a client struggling with manual invoice creation and inconsistent payment follow-up. The system, built entirely in n8n, handles the full invoice lifecycle without manual intervention.

The problem: The client was manually generating invoices, tracking due dates in spreadsheets, and sending payment reminders by hand, a process that ate hours weekly and led to missed follow-ups on overdue accounts.

An automated pipeline that generates a branded PDF invoice on request, emails it to the customer, and archives a copy to Google Drive

A daily scheduled check that identifies overdue invoices and applies smart logic to determine reminder timing

An AI agent (using Groq/GPT models) that writes personalized reminder emails per customer instead of static templates, then logs each reminder to the database automatically

A webhook-based payment detection system that updates payment status in real time and triggers an automatic confirmation message to the customer

A weekly summary report generated and delivered directly to the finance team

Outcome: The client's invoicing and follow-up process now runs fully in the background, with no manual invoice creation, no missed reminders, and finance stays updated without needing to ask.