The problem

A small services company has 80,000 MAD stuck in unpaid invoices. The founder hates chasing clients, forgets who was reminded when, and cash-flow suffers every month.

The solution, step by step

  1. Keep the invoice log in Google Sheets: client, email, amount, due date, status, last reminder date.
  2. An n8n workflow runs every morning and computes the days overdue for each unpaid invoice.
  3. Prepare three escalating email templates: friendly reminder at D+7, firm reminder with the invoice attached at D+15, formal notice mentioning next steps at D+30.
  4. The workflow personalizes the right template (name, amount, invoice number) and sends it via Gmail.
  5. Each send is logged back in the sheet, so nobody is ever reminded twice for the same step.
  6. When a payment is marked received, the workflow sends a short thank-you message — reminders stay courteous and the relationship stays healthy.
  7. Result and estimated gains

    • Average payment delay typically reduced by 30 to 50% within a quarter.
    • Around 3 hours per week saved on manual follow-up.
    • A complete, dated reminder history for every invoice — useful if a dispute ever arises.