n8n Workflow: Google Sheets Certificate Expiry Email Alerts

Never miss a certificate expiry again—automated Google Sheets alerts with escalating email reminders

This n8n workflow checks your Google Sheets compliance register every day at 7am, calculates certificate expiry dates, and automatically sends urgent expiry and renewal reminder emails via SMTP—stopping silently when nothing is due.

What this workflow does

• Runs on a daily schedule (by default at 7am).
• Reads expiry records from a Google Sheets compliance register containing expiry dates.
• Calculates days remaining for each row and groups items into:
  • Already expired
  • Within 7 days
  • Within 30 days
  • Within 90 days
• Prevents unnecessary emails: if there are no items due or expired, it stops without sending anything.
• Escalates for urgency: if one or more items are already expired, it sends an urgent email (optionally including items expiring within 7 days).
• Tracks renewals: when no expired items exist, it sends a renewals summary email; the 90-day horizon list is included only on Mondays.

Use cases

• Monitor certificate compliance (e.g., security or regulatory documents) stored in Google Sheets.
• Send escalating expiry alerts to owners and renewal contacts via email (SMTP).
• Reduce administrative overhead for SaaS operations teams and automation engineers using n8n.
• Maintain consistent compliance checks with a schedule-triggered workflow rather than manual reviews.

Technical details

• Schedule Trigger runs daily at 7am (cron adjustable).
• Google Sheets read step to load the compliance register.
• Code logic to calculate days remaining and group rows by expiry windows.
• if nodes to decide whether to stop or send emails based on due/expired items and Monday logic.
• Email Send (SMTP) for alert delivery (replace the recipient like owner@example.com in both email steps).
• Sticky Note nodes for workflow guidance.

Setup requirements

• Google account access to the Sheets register.
• SMTP (or Gmail-capable) credentials for email alerts.
• An n8n instance (cloud or self-hosted) capable of running the daily schedule.