# Automate GST/VAT tax returns with OpenAI and Gmail: n8n workflow

> Started by a clock, and works across Gmail. It hands the judgement calls to OpenAI. 19 steps, 2 branches: a working afternoon to understand properly.

Source: https://millionrounds.com/workflow/automate-gst-vat-tax-returns-with-openai-and-gmail (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)

# Automate GST/VAT tax returns with OpenAI and Gmail

Started by a clock, and works across Gmail. It hands the judgement calls to OpenAI. 19 steps, 2 branches: a working afternoon to understand properly.

Medium Calls a model: OpenAI

[Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fautomate-gst-vat-tax-returns-with-openai-and-gmail)

**19 steps** Medium: a working afternoon

**2** Branches: places the flow splits

**0** Loops or waits

**1** Service it connects to

## The flow

Starts it 1 Model 4 Logic 8 Service 6

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

- 1 **Monthly Tax Return Schedule** Schedule trigger *Starts it*
- 2 **OpenAI Chat Model** Lm Chat Open Ai *Model*
- 3 **Tax Calculation Output Parser** Output Parser Structured *Model*
- 4 **Calculator Tool** Tool Calculator *Model*
- 5 **Workflow Configuration** Set *Logic*
- 6 **Tax Validation & Calculation Agent** Agent *Model*
- 7 **Fetch Expenses Data** Http Request *Service*
- 8 **Fetch Invoices Data** Http Request *Service*
- 9 **Fetch Revenue Data** Http Request *Service*
- 10 **Check Tax Threshold** If *Logic*
- 11 **Merge Financial Data** Set *Logic*
- 12 **Generate Tax Declaration** Set *Logic*
- 13 **Below Threshold Notice** Set *Logic*
- 14 **Submit to Government Portal** Http Request *Service*
- 15 **Send to Tax Agent** Gmail *Service*
- 16 **Log Confirmation** Set *Logic*
- 17 **Check Tax Owed** If *Logic*
- 18 **Send Payment Reminder** Gmail *Service*
- 19 **No Action Required** Set *Logic*

## How it's built

- **Starts on:** A clock
- **Steps:** 19, with 2 branches
- **Size:** Medium: a working afternoon
- **Connects to:** Gmail
- **Model:** OpenAI

## Questions

What does it need to run?

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

What starts it?

It starts on a clock.

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. 19 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 19 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%2Fautomate-gst-vat-tax-returns-with-openai-and-gmail)
- **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)

## Workflows like it

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

- [**Intelligent invoice processing & notification agent** 19 steps · calls a model · Gmail, Slack](https://millionrounds.com/workflow/intelligent-invoice-processing-and-notification-agent)
- [**Match supplier invoices to purchase orders with Gmail** 19 steps · calls a model · Gmail, n8n data table](https://millionrounds.com/workflow/match-supplier-invoices-to-purchase-orders-with-gmail)
- [**Process invoices and send weekly AI reports with OpenAI** 19 steps · calls a model · Gmail, n8n data table](https://millionrounds.com/workflow/process-invoices-and-send-weekly-ai-reports-with-openai)
- [**Automated event management with Typeform and Stripe** 19 steps · Gmail, Google Calendar](https://millionrounds.com/workflow/automated-event-management-with-typeform-and-stripe)
- [**Collect overdue payments with Slack** 19 steps · Gmail, Slack](https://millionrounds.com/workflow/collect-overdue-payments-with-slack)
- [**Approve employee expenses with OpenAI and Google Sheets** 18 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/approve-employee-expenses-with-openai-and-google-sheets)