Chase overdue invoice payments with Google Sheets, Gemini, Gmail and Slack
Ready for 3.0Ready for 3.0. This template uses no nodes that n8n 3.0 removes. No removed nodes, versions or helpers found. Static check, last run 2026-10-19.
What this workflow does
This AI workflow has 11 nodes and runs on a schedule (every day at 09:00). Along the way it connects Google Sheets, Google Gemini Chat Model, Gmail and Slack.
How it runs
Trigger: On a schedule (every day at 09:00).
- Get Unpaid Invoices (Google Sheets): uses Google Sheets
- Compute Days Overdue (Code): runs custom JavaScript code
- Write Reminder with Gemini (Basic LLM Chain): sends a prompt to an LLM, with model: Google Gemini Chat Model
- Route by Stage (Switch): routes items into 3 branches
- Send Gentle Reminder (Gmail): uses Gmail
- Send Firm Reminder (Gmail): uses Gmail
- Send Final Notice (Gmail): uses Gmail
- Update Last Reminder (Google Sheets): append or update
- Alert Finance Team (Slack): uses Slack
Services it uses
Before you upgrade to n8n 3.0
Nothing in this workflow is removed in n8n 3.0, so it should import and run after the upgrade.
Nodes used (8)
- Schedule Trigger
n8n-nodes-base.scheduleTrigger - Google Sheets
n8n-nodes-base.googleSheets - Code
n8n-nodes-base.code - Basic LLM Chain
@n8n/n8n-nodes-langchain.chainLlm - Google Gemini Chat Model
@n8n/n8n-nodes-langchain.lmChatGoogleGemini - Switch
n8n-nodes-base.switch - Gmail
n8n-nodes-base.gmail - Slack
n8n-nodes-base.slack
From the author
Quick Overview This workflow runs daily, reads unpaid invoices from Google Sheets, uses Google Gemini to draft stage-appropriate reminder emails, sends them via Gmail, optionally alerts a Slack finance channel for long-overdue invoices, and updates the…