AI Invoice Reminder & Payment Tracker n8n Workflow (9AM)

Automatically remind clients about overdue invoices at 9 AM—then track payments in real time

This AI Invoice Reminder & Payment Tracker n8n workflow (9AM) automates invoice follow-ups end-to-end: it checks pending invoices every day at 9 AM, uses AI to generate personalized reminder emails, sends them to clients, and continuously tracks payment updates via webhooks—with daily summaries for your finance team.

What this workflow does

• Schedule Daily Check (9 AM): the workflow runs every day at 9 AM to start the process.
• Fetch Pending Invoices: queries your Postgres database for unpaid invoices.
• Filter Overdue Invoices: separates overdue invoices using due dates so you only chase what’s late.
• Calculate Reminder Logic: applies smart timing/urgency logic to decide when and how reminders should be sent.
• Prepare AI Prompt: formats invoice data into a tailored prompt for the AI agent.
• Generate Email (AI Agent): creates a personalized reminder email for each client.
• Format Email: styles the reminder as HTML for a professional look.
• Send Email Reminder: delivers the email to the client.
• Update Reminder Status + logs: records that a reminder was sent, creates an activity log, and saves raw input for auditing/analysis.
• Payment tracking via webhooks: listens for payment updates, updates invoice status, and feeds the daily visibility.
• Generate Daily Summary: produces a report for the finance team with activity and outcomes.

Use cases

• Send consistent, on-time invoice reminders without manual spreadsheet work.
• Reduce days sales outstanding (DSO) by escalating overdue items using reminder logic.
• Get daily finance reporting and auditable logs for every reminder and payment update.

Technical details

• Nodes/tech stack: if, set, code, webhook, postgres, email send
• Integrations: Postgres (invoice data + status updates), webhook (payment updates), email send (HTML reminders)