Automate invoice processing with OCR.Space, GPT-4 & Google Drive to Gmail

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

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

2. 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.

3. 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.

4. 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.

5. 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.

6. 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