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Classify & auto-sort invoices in Google Drive with GPT-4o

Rahul JoshiRahul Joshi
537 views
2/3/2026
File ManagementAWS S3Cloud StorageSynchronizationGoogle Drive
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Description:

Automatically classify invoices by industry (Retail, Manufacturing, or EdTech) using GPT-4o-powered AI parsing in this intelligent n8n automation template. Designed for teams managing high-volume billing data, this workflow fetches invoices from Google Drive, extracts PDF text, classifies each document using AI, and automatically moves files to the correct folder based on the predicted industry.

This smart auto-sorting system turns your invoice processing into a zero-touch AI workflow—ideal for finance teams, document processing agencies, and operations managers dealing with multi-client or multi-industry invoicing pipelines.

What This Template Does (Step-by-Step)

📂 Google Drive Search

  • Scans a designated folder (e.g., “Incoming Invoices”)
  • Collects all PDF files available for classification

⬇️ Download & Extract PDF Text

  • Downloads each file using Google Drive API
  • Extracts invoice text from PDFs using the “Extract from File” node

🔁 Batch Handling

  • Loops through each invoice in a batch using the SplitInBatches node
  • Ensures each document is processed one at a time

🧠 GPT-4o Mini via LangChain Agent

  • Sends extracted invoice content to GPT-4o AI
  • Classifies the document into one of: Retail, Manufacturing, EdTech
  • Returns clean, structured classification output

🔀 Smart Switch Logic

  • Evaluates the classification result
  • Routes the invoice to the correct folder based on its predicted industry

📁 Auto-Move Files

  • Uses Google Drive API to move files into industry-specific folders:
  • Retail → Folder A
  • Manufacturing → Folder B
  • EdTech → Folder C

Required Integrations:

✅ Google Drive (OAuth2 authentication) ✅ Azure OpenAI (GPT-4o or compatible model) ✅ LangChain agent setup in n8n

Best For:

🧾 Finance teams classifying vendor or client invoices 🏭 Companies handling multi-industry procurement 🧠 AI automation agencies building custom document sorters 🗂️ Back-office automation for Google Drive file workflows

Key Benefits:

💡 No manual labeling required — AI classifies based on content 📦 Automatically moves files to clean, organized folders 🔄 Works in batch mode for bulk invoice handling 💬 Simple prompt customization for other classification types 🧠 GPT-4o-powered classification ensures high accuracy

Classify and Auto-Sort Invoices in Google Drive with GPT-4o

This n8n workflow automates the process of extracting information from invoice PDFs in Google Drive, classifying them using an AI agent, and then sorting them into appropriate folders. This streamlines invoice management and reduces manual effort.

What it does

  1. Manual Trigger: The workflow is initiated manually, allowing you to run it on demand.
  2. Google Drive File Listing: It lists all PDF files from a specified folder in Google Drive (e.g., an "Unsorted Invoices" folder).
  3. Loop Over Items: Each identified PDF file is processed individually in a loop.
  4. Extract from File: For each PDF, the workflow extracts its content (text) to be analyzed.
  5. AI Agent (GPT-4o): An AI agent, powered by an Azure OpenAI Chat Model (likely GPT-4o, given the directory name), analyzes the extracted text from the invoice. Its role is to:
    • Identify key information (e.g., vendor, amount, date).
    • Classify the invoice type (e.g., utility, software, travel).
    • Determine the correct target folder based on the classification.
  6. Switch Node: Based on the AI agent's classification, the workflow routes the invoice to the appropriate branch. This allows for different actions based on the invoice type.
  7. Google Drive File Movement: The workflow moves the processed invoice PDF from the initial unsorted folder to its newly determined, categorized folder in Google Drive.

Prerequisites/Requirements

  • n8n Instance: A running n8n instance.
  • Google Drive Account: A Google Drive account with a designated "Unsorted Invoices" folder and pre-existing categorized folders (e.g., "Utilities," "Software," "Travel") where invoices will be moved.
  • Azure OpenAI Service: Access to Azure OpenAI Service with a deployed chat model (e.g., GPT-4o) and an associated API key.
  • n8n Credentials: Configured n8n credentials for:
    • Google Drive (OAuth2 or API Key).
    • Azure OpenAI Chat Model (API Key and endpoint details).

Setup/Usage

  1. Import the Workflow: Import the provided JSON into your n8n instance.
  2. Configure Credentials:
    • Update the "Google Drive" node with your Google Drive credentials. Ensure the service account or OAuth scope has permission to list files, read file content, and move files within your Google Drive.
    • Update the "Azure OpenAI Chat Model" node with your Azure OpenAI Service credentials, including your API key, resource name, and deployment name.
  3. Specify Google Drive Folders:
    • In the "Google Drive" node (the first one listing files), configure the "Folder ID" to point to your "Unsorted Invoices" folder.
    • In the "Switch" node, configure the conditions to match the classifications provided by your AI agent and define the output branches.
    • In the subsequent "Google Drive" nodes (for moving files, not explicitly shown in the JSON but implied by the "Switch" node's purpose), configure the "Destination Folder ID" for each categorized folder.
  4. Customize AI Agent Prompt: Review and potentially customize the prompt within the "AI Agent" node to optimize invoice classification for your specific needs and invoice types.
  5. Execute Workflow: Click the "Execute workflow" button to run the workflow. It will process all PDF invoices in your specified unsorted folder.

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