🧾 Extract invoice data from Slack PDFs to Google Sheets with GPT-4o
⚡ 291 views · 🧾 Invoice Processing
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Description
Managing invoices manually can be time-consuming and error-prone. This workflow automates the process by extracting key invoice details from PDFs shared in Slack, structuring the information with AI, saving it to Google Sheets, and sending a confirmation back to Slack. It’s a seamless way to keep your financial records organized without manual data entry.
How it works
- Receive invoice in Slack – When a PDF invoice is uploaded to a designated Slack channel, the workflow is triggered.
- Fetch the PDF – The file is downloaded automatically for processing.
- Extract data from PDF – Basic text extraction is performed to capture invoice content.
- AI-powered invoice parsing – An AI model interprets the extracted text and structures essential fields such as company name, invoice number, total amount, invoice date, and due date.
- Save to Google Sheets – The structured invoice data is appended as a new row in a Google Sheet for easy tracking and reporting.
- Slack confirmation – A summary of the saved invoice details is sent back to Slack to notify the team.
How to use
- Import the workflow into your n8n instance.
- Connect Slack – Authenticate your Slack account and set up the trigger channel where invoices will be uploaded.
- Connect Google Sheets – Authenticate with Google Sheets and specify the target spreadsheet and sheet name.
- Configure the AI extraction – Adjust the parsing prompt or output structure to fit your preferred data fields (e.g., vendor name, invoice ID, amount, dates).
- Test the workflow – Upload a sample invoice PDF in Slack and verify that the data is correctly extracted and saved to Google Sheets.
Requirements
- An n8n instance (cloud)
- Slack account with permission to read uploaded files and post messages
- Google account with access to the spreadsheet you want to update
- AI integration (e.g., OpenAI GPT or another LLM with PDF parsing capabilities)
- A designated Slack channel for receiving invoice PDFs
🔗 Nodes Used
Google Sheets, HTTP Request, Slack, AI Agent, OpenAI Chat Model, Structured Output Parser
📥 Import
Download workflow.json and import into n8n:
Workflow menu → Import from File