# Automated invoice workflow with Google Workspace: n8n workflow

> Started by a change in a Google Sheet, and works across Gmail, Google Docs, Google Sheets and Slack. It hands the judgement calls to OpenAI.

Source: https://millionrounds.com/workflow/automated-invoice-workflow-with-google-workspace (Millionrounds; every figure on the page links to its filing or article)

[Automation library](https://millionrounds.com/workflows) · [Money admin](https://millionrounds.com/workflows?category=Money+admin#library)

# Automated invoice workflow with Google Workspace

Started by a change in a Google Sheet, and works across Gmail, Google Docs, Google Sheets and Slack. It hands the judgement calls to OpenAI. 11 steps, 1 branch, 2 loops or waits: a working afternoon to understand properly.

Medium Calls a model: OpenAI

[Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fautomated-invoice-workflow-with-google-workspace)

**11 steps** Medium: a working afternoon

**1** Branch: places the flow splits

**2** Loops or waits

**4** Services it connects to

## The flow

Starts it 1 Model 1 Logic 3 Service 6

The steps in the order they run, from what starts it.

- 1 **Google Sheets Trigger** Google Sheets trigger *Starts it*
- 2 **AI Invoice Content Generation** Open Ai *Model*
- 3 **Create Invoice from Template** Google Docs *Service*
- 4 **Send Invoice** Gmail *Service*
- 5 **Until 3 Days Before Due Date** Wait *Logic*
- 6 **Check Payment Status** Http Request *Service*
- 7 **Is Paid?** If *Logic*
- 8 **Pre-Due Reminder** Gmail *Service*
- 9 **Update Status** Google Sheets *Service*
- 10 **Until 2 Days After Due Date** Wait *Logic*
- 11 **Overdue Alert** Slack *Service*

## How it's built

- **Starts on:** A change in a Google Sheet
- **Steps:** 11, with 1 branch, 2 loops or waits
- **Size:** Medium: a working afternoon
- **Connects to:** Gmail, Google Docs, Google Sheets, Slack
- **Model:** OpenAI

## Questions

What does it need to run?

An n8n account, plus your own Gmail, Google Docs, Google Sheets and Slack accounts, and a key for OpenAI. You connect your own accounts after importing it; none are included.

What starts it?

It starts on a change in a Google Sheet.

Does it use AI?

Yes. It calls OpenAI. Model calls are billed by the provider, not by n8n.

How long does it take to set up?

Plan an afternoon. 11 steps is enough that you should read each one before running it.

How do I import it?

Copy the workflow, open a new workflow in n8n and paste. The steps appear on the canvas, ready for your own accounts.

**Before you run it**

Nothing here has been tested by us. It is somebody's working automation, read and described from its own steps. Treat the connections it wants as a list of accounts it will touch, and read the 11 steps before you point it at anything that matters.

## Run it in n8n

- **Create your n8n account** Free to start. n8n is where the workflow runs. [Create an n8n account ↗](https://millionrounds.com/n8n)
- **Download the workflow** Free with a Millionrounds account. [Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fautomated-invoice-workflow-with-google-workspace)
- **Paste it into n8n** Open a new workflow in n8n and paste. Then connect your own accounts.

Stored with the author's traces removed: canvas notes, instance identifiers, saved credential names and any live document they had left behind.

## Connects to

Each opens the other workflows that use it.

[Gmail](https://millionrounds.com/workflows?service=Gmail#library)[Google Docs](https://millionrounds.com/workflows?service=Google+Docs#library)[Google Sheets](https://millionrounds.com/workflows?service=Google+Sheets#library)[Slack](https://millionrounds.com/workflows?service=Slack#library)

## Workflows like it

Also money admin, with the same services where possible, closest in size first.

- [**AI invoice agent with OpenAI and Gmail** 11 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/ai-invoice-agent-with-openai-and-gmail)
- [**AI-powered invoice analysis & anomaly detection with OpenAI** 11 steps · calls a model · Airtable, Gmail](https://millionrounds.com/workflow/ai-powered-invoice-analysis-and-anomaly-detection-with-opena)
- [**Analyze invoices and predict cash flow with Gemini** 11 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/analyze-invoices-and-predict-cash-flow-with-gemini)
- [**Automate WhatsApp invoice processing with OCR and OpenAI** 11 steps · calls a model · Google Drive, Google Sheets](https://millionrounds.com/workflow/automate-whatsapp-invoice-processing-with-ocr-and-openai)
- [**Automate invoice generation & email delivery with Jotform** 11 steps · calls a model · Email, Slack](https://millionrounds.com/workflow/automate-invoice-generation-and-email-delivery-with-jotform)
- [**Automate invoice processing from Gmail with Azure GPT-4.1** 11 steps · calls a model · Gmail](https://millionrounds.com/workflow/automate-invoice-processing-from-gmail-with-azure-gpt-4-1)