Automatic invoice detection & reminder creation with Gmail & Google Tasks

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Important notice

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

1. Workflow Overview

This workflow contains community nodes that are only compatible with the self hosted version of n8n. Who is this for? This workflow is for anyone who receives invoices by email and wants to stay on...

Best for

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

Tools used

n8n-nodes-base.scheduletrigger, @n8n/n8n-nodes-langchain.agent, @n8n/n8n-nodes-langchain.lmchatopenai, @n8n/n8n-nodes-langchain.outputparserstructured, n8n-nodes-base.noop, n8n-nodes-base.googletasks, n8n-nodes-base.gmail, n8n-nodes-base.if

Source and attribution

This workflow is cataloged by N8N Workflows and links back to its original n8n.io source page by Matt Chong | n8n Creator.

Original n8n.io source

1.1 Workflow description

Title: Automatic invoice detection & reminder creation with Gmail & Google Tasks
Workflow name: Automatic invoice detection & reminder creation with Gmail & Google Tasks

This workflow contains community nodes that are only compatible with the self-hosted version of n8n.

Who is this for?

This workflow is for anyone who receives invoices by email and wants to stay on top of payment deadlines without manual tracking.

What problem is this workflow solving?

Invoices often get buried in your inbox. This workflow uses AI to find them, extracts key details, and adds a task to remind you to pay before it’s overdue.

No more missed payments. No more manual tracking.

How it works?

This workflow is triggered on a schedule (By default, every hour).
It checks your Gmail inbox for unread messages.
Each email is passed to an AI agent (using OpenAI), which decides whether it’s an invoice.
If an invoice is found:
- A task is created in your Google Tasks with the payment reminder and due date.
- The email is labeled (for tracking) and marked as read.
If not an invoice:
- The email is skipped (no action taken).

How to set up?

Connect these services in your n8n credentials:
- Gmail (OAuth2)
- OpenAI
- Google Tasks
Create Gmail label
Go to Gmail and create a label named Invoice. This label will be applied to processed invoice emails.
Choose your Google Task list
In the task creation node, select the correct task list for your reminders.
Set the schedule
In the Schedule Trigger node, choose how often it should check your inbox.

How to customize this workflow to your needs?

Change the Gmail label
Update the label applied to emails after they are processed.
Edit the AI prompt
Adjust the system prompt in the OpenAI node if your invoices follow a unique format.
Update the task format
Modify the task title and notes to suit how you like your reminders to look.
Adjust the schedule
Run it more or less frequently based on how many invoices you receive.

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 - Schedule Trigger

Type / Role: n8n-nodes-base.scheduleTrigger - scheduleTrigger
Config choices: Version 1.2

Block 2 - AI Agent

Type / Role: @n8n/n8n-nodes-langchain.agent - agent
Config choices: Version 2.1

Block 3 - OpenAI Chat Model

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

Block 4 - Structured Output Parser

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

Block 5 - No Operation, do nothing

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

Block 6 - Create a task

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

Block 7 - Add Label to Email

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

Block 8 - Mark Email as read

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

Block 9 - Get Unread Emails

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

Block 10 - Check If Email is Invoice

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

Block 11 - Sticky Note

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

Block 12 - Sticky Note2

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

Block 13 - Sticky Note1

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

3. Summary Table

Workflow	Automatic invoice detection & reminder creation with Gmail & Google Tasks
Complexity	intermediate
Nodes	13
Categories	Invoice Processing, AI Summarization
Author	Matt Chong \| n8n Creator
Published	11 Jul 2025

4. Reproducing the Workflow from Scratch

1. Download the workflow JSON

Use the JSON export at /data/workflows/5863/5863.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 Automatic invoice detection & reminder creation with Gmail & Google Tasks 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.

Matt Chong | n8n Creator

10 workflows

Nodes

n8n-nodes-base.scheduletrigger @n8n/n8n-nodes-langchain.agent @n8n/n8n-nodes-langchain.lmchatopenai @n8n/n8n-nodes-langchain.outputparserstructured n8n-nodes-base.noop n8n-nodes-base.googletasks n8n-nodes-base.gmail n8n-nodes-base.if

Complexity

intermediate

Published 11 Jul 2025

Likes 0

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Install path: /data/workflows/5863/5863.json

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Automatic invoice detection & reminder creation with Gmail & Google Tasks

Workflow preview

Important notice

1. Workflow Overview

Best for

Tools used

Source and attribution

1.1 Workflow description

Who is this for?

What problem is this workflow solving?

How it works?

How to set up?

How to customize this workflow to your needs?

1.2 Logical Blocks

2. Block-by-Block Analysis

Block 1 - Schedule Trigger

Block 2 - AI Agent

Block 3 - OpenAI Chat Model

Block 4 - Structured Output Parser

Block 5 - No Operation, do nothing

Block 6 - Create a task

Block 7 - Add Label to Email

Block 8 - Mark Email as read

Block 9 - Get Unread Emails

Block 10 - Check If Email is Invoice

Block 11 - Sticky Note

Block 12 - Sticky Note2

Block 13 - Sticky Note1

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