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Automate Overdue Invoice Reminders with Zapier Agents
Automatically check your invoices spreadsheet each morning, email overdue customers a payment reminder, and log the sent date, saving you manual effort and ensuring timely follow‑ups.
The Workflow
9 steps · click a step number to mark it done
Open zapier and have it ready before you start
Log in to Zapier and open the left‑hand navigation, then click the Agents section
Click “Create a custom agent” and type a plain‑English instruction such as: “Every day at 8 AM, look up rows in the Invoices Google Sheet where the invoice is unpaid and past due, email the customer a friendly reminder, and record the reminder date in the sheet”
Add a tool by clicking the settings gear and selecting Gmail → Send Email, then connect your Gmail account
Add another tool: Google Sheets → Lookup Spreadsheet Rows, and configure it to search the invoice sheet for rows with Paid = false and Due Date before today
Add a third tool: Google Sheets → Update Spreadsheet Row, set it to write the current date into the “Reminder Sent” column after the email is sent
Set the trigger to “Scheduled by Zapier” and choose 8:00 AM as the run time
Click “Test agent”, answer the prompt with the exact name of your invoice sheet (e.g., Invoices‑KCC Billing), and approve the suggested actions
Toggle the agent switch on in the top‑right corner to enable automatic daily runs
Visit the All Activity tab periodically to verify successful runs and troubleshoot any errors