Automating Invoice Processing and Payment Reminders with n8n, Mistral AI, and Azure

I recently helped a small home construction business transform their invoice management workflow. Their team was spending hours every day manually processing vendor invoices, which was both time-consuming and error-prone.

The construction company receives 10-12 vendor invoices daily, all uploaded to their Azure blob storage. Their process involved:

• Manually downloading each invoice PDF from Azure blob storage
• Extracting key details (vendor name, amount, due date, invoice number) by hand
• Entering all information into Google Sheets
• Tracking payment due dates manually
• Writing and sending reminder emails to the accounts team

This manual workflow was eating up several hours each day and frequently resulted in missed payments or data entry errors.

Solution

I built a fully automated invoice processing system using n8n, Mistral AI, OpenAI, and Azure SQL Database.

Here's how the automation works:

Daily Processing:

• Scheduled workflow runs every morning to scan Azure blob storage
• Automatically downloads any new invoice PDFs
• Uses Mistral AI's OCR capabilities to extract key data from each invoice
• Structures and cleans the extracted information
• Saves all invoice details to Azure SQL database

Payment Reminders:

• Queries the database for invoices due within the next 15 days
• Sends due invoice data to OpenAI for processing
• AI generates professional reminder emails with relevant details
• Automatically sends emails to the accounts team via Outlook

How AI Makes a Difference

Mistral AI for OCR: Mistral's document processing capabilities handle various invoice formats reliably, extracting vendor details, amounts, and due dates with high accuracy.

n8n for Orchestration: n8n's workflow automation made it easy to connect Azure storage, AI services, and email systems without complex coding.

Azure SQL for Data Management: Storing invoice data in a structured database enables easy querying and reporting for payment tracking.

Result

The construction company now processes all vendor invoices automatically. The system runs every morning, extracting invoice details and ensuring the accounts team receives timely payment reminders.

This automation saves several hours daily and has eliminated data entry errors. The team can now focus on core business activities instead of manual invoice processing.

Final Thoughts

This project demonstrates how combining AI with workflow automation can streamline repetitive business processes. For small businesses handling high volumes of documents, automated data extraction and processing can be a game-changer.

If you're dealing with similar manual document processing workflows, there are smart automation solutions that can help. I'd be happy to discuss options tailored to your specific needs.