Overview
Trello cards with due dates only matter if someone actually sees them in time. The default Trello due date notification often gets buried in email or ignored. This automation uses Zapier to send proactive reminders — a Slack message or email — 24 or 48 hours before a card's due date, directly to the assigned team member. Small teams using this report a 50% reduction in missed deadlines from overlooked Trello cards.
Before you start
- Trello account (Butler available on free plan for basic rules)
- Zapier free or Starter plan for Slack integration
- Slack workspace (optional but recommended)
Step-by-step guide (4 steps)
Enable Trello's native due date reminders
In Trello, click your avatar → Notifications → enable 'Card due date' notifications. This sends an in-app and email notification 24 hours before due dates. This is your zero-effort starting point.
Set up a Zapier reminder for Slack
For team-wide visibility, create a Zapier Zap: trigger on 'Card Due Date Approaching' in Trello (available in Zapier's Trello triggers). Set the lead time to 24 hours. Action: send a Slack message to the card member with the card name and due date.
Map the Trello card member's Trello username to their Slack user ID using a lookup table in Zapier. This sends a direct Slack DM instead of a channel message.
Add a second reminder for overdue cards
Create a second Zap triggered by 'Card Overdue' in Trello. Send a higher-priority Slack alert or email to both the card member and their manager. Include the card link and a clear message: 'This task is now overdue — please update the card status.'
Use Butler automation for in-Trello reminders
In Trello, go to Butler (built-in automation) → Scheduled Commands. Create a rule: every day at 9 AM, if a card on this board is due within 48 hours, add a comment '@member — this is due in 2 days'.
Butler's comment-based reminders show up in the card activity and trigger Trello's own notification system, so members get notified even without Zapier.
What you'll get
Deadlines are flagged before they're missed, not after
Team members don't need to check Trello daily to stay on track
Managers get visibility into overdue work without micromanaging
Reduces client escalations from missed internal deadlines
Common mistakes to avoid
Relying only on Trello's email notifications, which team members often ignore
Not setting due dates on cards at creation time — reminders can't work without them
Sending reminders too early (1 week out) or too late (day of), losing the action window
Sending overdue alerts to a shared channel instead of the responsible member directly
Frequently asked questions
Do I need coding experience to set up this Trello automation?
No coding is required. This guide walks you through everything using Trello's built-in features and Zapier's visual interface. If you can follow a recipe, you can follow this guide.
How long does this automation take to set up?
Most users complete this setup in 30–60 minutes on their first try. Once set up, it runs completely automatically with zero ongoing effort.
What happens if the automation fails?
Zapier and Make both have error notifications and task history, so you'll know immediately if something goes wrong. We cover troubleshooting steps in the guide above.
Can I customize this automation for my specific business?
Absolutely. The guide includes notes on common customizations. Most automations have multiple variation points — timing, conditions, notification recipients, and more.