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

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Important notice

This workflow is provided as-is. Please review and test before using in production.

1. Workflow Overview

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....

Best for

Invoice Processing automation workflows
AI Summarization automation workflows
advanced n8n builders looking for reusable templates

Tools used

n8n-nodes-base.merge, n8n-nodes-base.splitinbatches, n8n-nodes-base.httprequest, n8n-nodes-base.googledrive, n8n-nodes-base.googlesheetstool, @n8n/n8n-nodes-langchain.lmchatopenai, @n8n/n8n-nodes-langchain.agent, n8n-nodes-base.set

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Michael Taleb.

Original n8n.io source

1.1 Workflow description

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

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

1.2 Logical Blocks

This catalog entry is organized from the workflow JSON. The node-level section below shows the executable blocks available for review before importing the template.

2. Block-by-Block Analysis

Block 1 - Merge

Type / Role: n8n-nodes-base.merge - merge
Config choices: Version 3

Block 2 - Loop Over Items

Type / Role: n8n-nodes-base.splitInBatches - splitInBatches
Config choices: Version 3

Block 3 - HTTP Request1

Type / Role: n8n-nodes-base.httpRequest - httpRequest
Config choices: Version 4.2

Block 4 - Google Drive

Type / Role: n8n-nodes-base.googleDrive - googleDrive
Config choices: Version 3

Block 5 - Google Sheets

Type / Role: n8n-nodes-base.googleSheetsTool - googleSheetsTool
Config choices: Version 4.5

Block 6 - OpenAI Chat Model

Type / Role: @n8n/n8n-nodes-langchain.lmChatOpenAi - lmChatOpenAi
Config choices: Version 1.2

Block 7 - AI Agent

Type / Role: @n8n/n8n-nodes-langchain.agent - agent
Config choices: Version 1.7

Block 8 - Edit Fields

Type / Role: n8n-nodes-base.set - set
Config choices: Version 3.4

Block 9 - Code

Type / Role: n8n-nodes-base.code - code
Config choices: Version 2

Block 10 - No Operation, do nothing

Type / Role: n8n-nodes-base.noOp - noOp
Config choices: Version 1

Block 11 - Merge1

Type / Role: n8n-nodes-base.merge - merge
Config choices: Version 3

Block 12 - No Operation, do nothing1

Type / Role: n8n-nodes-base.noOp - noOp
Config choices: Version 1

Block 13 - Error

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 14 - Send Email

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 15 - Error1

Type / Role: n8n-nodes-base.gmail - gmail
Config choices: Version 2.1

Block 16 - If

Type / Role: n8n-nodes-base.if - if
Config choices: Version 2.2

Block 17 - Structured Output Parser1

Type / Role: @n8n/n8n-nodes-langchain.outputParserStructured - outputParserStructured
Config choices: Version 1.3

Block 18 - Sticky Note1

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 19 - Sticky Note2

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 20 - Sticky Note3

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 21 - Sticky Note4

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 22 - Sticky Note5

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 23 - Sticky Note6

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Block 24 - Sticky Note7

Type / Role: n8n-nodes-base.stickyNote - stickyNote
Config choices: Version 1

Showing the first 24 of 29 workflow blocks. Download the JSON for the full node graph.

3. Summary Table

Workflow	Automate invoice processing with OCR.Space, GPT-4 & Google Drive to Gmail
Complexity	advanced
Nodes	29
Categories	Invoice Processing, AI Summarization
Author	Michael Taleb
Published	02 Sept 2025

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/8139/8139.json as the source template for this automation.
2. Import the template into n8n

Open n8n, import the downloaded JSON, and review each node before activating the workflow.
3. Configure credentials and variables

Replace placeholder credentials, API keys, webhook URLs, account IDs, and environment-specific values with your own settings.
4. Test with sample data

Run the workflow manually or in a staging workspace, inspect node output, and confirm downstream systems receive the expected data.
5. Activate and monitor

Enable the workflow only after testing, then monitor executions, errors, and rate limits during the first production runs.

5. General Notes & Resources

Review imported nodes carefully before activation. This catalog entry is intended to help you inspect the workflow structure, understand required services, and find related templates faster.

Node names, credentials, schedules, webhook paths, and external service limits may need adjustment for your workspace.

Download workflow JSON Original n8n.io source Invoice Processing workflows AI Summarization workflows

Frequently asked questions

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

What do I need before importing this workflow?

Review the workflow JSON, configure any required credentials in n8n, and test the automation in a safe workspace before using it in production.

Can I customize this workflow?

Yes. Use the block-by-block analysis and the downloadable JSON to inspect each node, then adjust credentials, prompts, schedules, filters, or destinations for your Invoice Processing, AI Summarization use case.

Michael Taleb

3 workflows

Nodes

n8n-nodes-base.merge n8n-nodes-base.splitinbatches n8n-nodes-base.httprequest n8n-nodes-base.googledrive n8n-nodes-base.googlesheetstool @n8n/n8n-nodes-langchain.lmchatopenai @n8n/n8n-nodes-langchain.agent n8n-nodes-base.set

Complexity

advanced

Published 02 Sept 2025

Likes 0

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Install path: /data/workflows/8139/8139.json

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

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

How it works

Setting up the workflow

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Merge

Block 2 - Loop Over Items

Block 3 - HTTP Request1

Block 4 - Google Drive

Block 5 - Google Sheets

Block 6 - OpenAI Chat Model

Block 7 - AI Agent

Block 8 - Edit Fields

Block 9 - Code

Block 10 - No Operation, do nothing

Block 11 - Merge1

Block 12 - No Operation, do nothing1

Block 13 - Error

Block 14 - Send Email

Block 15 - Error1

Block 16 - If

Block 17 - Structured Output Parser1

Block 18 - Sticky Note1

Block 19 - Sticky Note2

Block 20 - Sticky Note3

Block 21 - Sticky Note4

Block 22 - Sticky Note5

Block 23 - Sticky Note6

Block 24 - Sticky Note7

3. Summary Table

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

2. Import the template into n8n

3. Configure credentials and variables

4. Test with sample data

5. Activate and monitor

5. General Notes & Resources

Frequently asked questions