# Submit and approve employee expenses with Odoo and Slack: n8n workflow

> Started by another system calling it, and works across Gmail and Slack. 18 steps, 3 branches: a working afternoon to understand properly.

Source: https://millionrounds.com/workflow/submit-and-approve-employee-expenses-with-odoo-and-slack (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)

# Submit and approve employee expenses with Odoo and Slack

Started by another system calling it, and works across Gmail and Slack. 18 steps, 3 branches: a working afternoon to understand properly.

Medium

[Download free](https://millionrounds.com/login?next=%2Fapp%2Fworkflow%2Fsubmit-and-approve-employee-expenses-with-odoo-and-slack)

**18 steps** Medium: a working afternoon

**3** Branches: places the flow splits

**0** Loops or waits

**2** Services it connects to

## The flow

Starts it 5 Logic 5 Service 8

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

- 1 **Webhook - Submit Expense** Webhook *Starts it*
- 2 **Validate & Normalize Expense Input** Set *Logic*
- 3 **IF - Input Valid?** If *Logic*
- 4 **Lookup Employee in Odoo** Odoo *Service*
- 5 **Respond 400 - Validation Error** Respond To Webhook *Starts it*
- 6 **IF - Employee Found?** If *Logic*
- 7 **Respond 500 - Processing Error** Respond To Webhook *Starts it*
- 8 **Lookup Expense Category in Odoo** Odoo *Service*
- 9 **Respond 404 - Employee Not Found** Respond To Webhook *Starts it*
- 10 **Create Expense in Odoo** Odoo *Service*
- 11 **Respond 202 - Expense Submitted** Respond To Webhook *Starts it*
- 12 **Slack - Manager Approval Request** Slack *Service*
- 13 **IF - Manager Approved?** If *Logic*
- 14 **Log Async Failure** No Op *Logic*
- 15 **Update Odoo Expense - Approved** Odoo *Service*
- 16 **Update Odoo Expense - Needs Correction** Odoo *Service*
- 17 **Gmail - Notify Employee Approved** Gmail *Service*
- 18 **Gmail - Notify Employee Rejected** Gmail *Service*

## How it's built

- **Starts on:** Another system calling it
- **Steps:** 18, with 3 branches
- **Size:** Medium: a working afternoon
- **Connects to:** Gmail, Slack
- **Model:** None. This is plumbing, not judgement

## Questions

What does it need to run?

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

What starts it?

It starts on another system calling it.

Does it use AI?

No. Every step is fixed logic or a call to a service, so it does the same thing every time.

How long does it take to set up?

Plan an afternoon. 18 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 18 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%2Fsubmit-and-approve-employee-expenses-with-odoo-and-slack)
- **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)[Slack](https://millionrounds.com/workflows?service=Slack#library)

## Workflows like it

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

- [**Create human-reviewed personalized PDFs from Stripe payments** 18 steps · Gmail, Google Sheets](https://millionrounds.com/workflow/create-human-reviewed-personalized-pdfs-from-stripe-payments)
- [**Process vendor invoices with UploadToURL and AWS Textract** 18 steps · Google Sheets, Slack](https://millionrounds.com/workflow/process-vendor-invoices-with-uploadtourl-and-aws-textract)
- [**Send proposal follow-ups and update deals with HubSpot** 18 steps · Gmail, Google Sheets](https://millionrounds.com/workflow/send-proposal-follow-ups-and-update-deals-with-hubspot)
- [**Send tiered payment reminders for overdue Odoo invoices** 18 steps · Gmail, Slack](https://millionrounds.com/workflow/send-tiered-payment-reminders-for-overdue-odoo-invoices)
- [**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)
- [**Audit expense reports with OpenAI and Slack** 18 steps · calls a model · Gmail, Google Sheets](https://millionrounds.com/workflow/audit-expense-reports-with-openai-and-slack)