Overview
Project completion milestones deserve acknowledgment and often trigger downstream actions — client notification, invoice creation, or archiving. But in Trello, project completion is invisible unless someone manually checks the board. This automation detects when a card moves to the 'Done' list and — when all cards are done — sends a Slack celebration message and triggers any next steps via Zapier. It creates a lightweight project lifecycle that closes the loop automatically.
Before you start
- Trello account (free plan works for basic Butler rules)
- Slack workspace
- Zapier free or Starter plan for Slack integration
Step-by-step guide (4 steps)
Set up a Trello trigger in Zapier for 'Card Moved to List'
In Zapier, create a Zap with Trello as the trigger: 'Card Moved to List'. Select your board and set the target list to 'Done' (or 'Complete', depending on your naming). Connect your Trello account.
Add a Slack notification action
Add Slack as the action: 'Send Channel Message'. Post to a #team or #wins channel: '🎉 [Card Name] has been completed on the [Board Name] project by [Member Name]. View the board: [Board URL]'.
Use a dedicated #wins or #shipped Slack channel for completion notifications. This keeps morale high and gives leadership visibility into throughput.
Trigger a next-step action (optional)
Add a second Zapier action based on what 'Done' means for your workflow. Examples: create a QuickBooks invoice, send a client email via Gmail, create a new Trello card in a 'Billing' board, or update a CRM deal stage.
Use Butler to auto-archive completed cards
In Trello Butler, create a rule: 'When a card is moved to the Done list, archive the card after 7 days'. This keeps the board clean without losing the history.
Instead of archiving immediately, use a '7-day archive' rule so team members have time to reference completed cards before they disappear from the board.
What you'll get
Project completions are celebrated and visible to the team
Next steps are triggered automatically — no manual handoffs
Board stays clean with auto-archiving of old cards
Managers get real-time visibility into what's being shipped
Common mistakes to avoid
Triggering on every card moved to Done instead of checking if all cards are done — fires too frequently
Not archiving completed cards, leading to cluttered boards over time
Sending notifications to a channel no one monitors
Forgetting to trigger downstream actions like invoicing or client notification
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.