Automate Invoice Processing with OCR.Space, GPT-4 & Google Drive to Gmail

Description

How it works
Watches a Google Drive folder for new (scanned) invoices. Each new file automatically triggers the workflow.
Downloads and processes each invoice through OCR Space to extract the text.
Extracts the company name (e.g. from the “billed to” field) and uses an AI agent to cross-reference it against a database in Google Sheets.
If a match is found, retrieves the correct recipient email and sends the invoice as an attachment.
If no match or an error occurs, the workflow alerts an operator by email for manual review.

Setting up the workflow

Connect Google Drive
• In n8n, connect your Google Drive account.
• Create or select a folder where you will upload scanned invoices.

Connect Gmail (or another email service)
• Add your Gmail account as a credential in n8n.
• This will be used to send the processed invoice to the correct recipient.

Set up OCR.Space
• Create a free OCR.Space account: https://ocr.space
• In n8n, create a Generic Credential (Header Auth).
• Use apikey as the name and your OCR API key as the value.

Connect the AI Agent
• Add your OpenAI API key as a credential in n8n.
• The AI Agent will extract the company name from the invoice text and match it against your database.
• If a match is found, it retrieves the correct email.

Prepare the Google Sheet database
• Make a copy of the database sheet: Google Sheet Template
• Fill it with company names and recipient emails.
• Connect your Google account to n8n and link this sheet to the workflow.

Run the workflow
• When a new invoice is uploaded to your Google Drive folder, the workflow will:
• Extract the text with OCR.Space
• Use the AI Agent to identify the company name
• Cross-reference it with your Google Sheet database
• Send the invoice automatically to the correct recipient via Gmail
• If no match is found, an error email is sent to you for manual review