Vendor Bills from Email to Odoo with n8n

n8n use case · Administration and finance

How to automate supplier invoice entry with n8n: invoices that arrive by email as PDFs are read by artificial intelligence, checked against duplicates and purchase orders, and saved as drafts in Odoo with a suggested accounting account. The accounting team stops typing and only reviews what falls outside the norm.

Information reviewed on 7 November 2026. Use case implemented with n8n by Binovo FutureAI, Certified n8n Expert Partner.

The problem

In most companies, the administration department receives dozens or hundreds of supplier invoices by email every month, each in its own format. Someone opens them, downloads them, types the supplier, date, tax base, VAT and lines into the ERP, and files the PDF. It is slow, errors slip in and, by the end of the month, the backlog piles up.

Common symptoms

  • Invoices that sit in the inbox and are posted late.
  • Typing errors in amounts or tax IDs.
  • Duplicate invoices that get paid twice.
  • Nobody knows what is pending approval.

What we aim for

  • Zero typing for standard invoices.
  • Automatic checks before posting.
  • Quick approval from email or chat.
  • The original PDF attached to each invoice in Odoo.

How n8n solves it, step by step

Scroll through the steps: on the right, the workflow node that is active at each moment is highlighted, along with the data it handles (sample data).

n8n workflow · Supplier invoicesExample
  • @Invoice mailboxTrigger: new email
  • IAAI reads the PDFData extraction
  • ?ValidationsBusiness rules
  • OOdooDraft invoice
  • ✓ApprovalHuman in the loop
  • iSummaryDaily tracking
email: facturas@tuempresa.es
from: proveedor@ejemplo.com
attachments: [FAC-2026-0412.pdf]
filter: is_invoice = true
supplier: Suministros Ejemplo SL
tax_id: B00000000
number: FAC-2026-0412
date: 2026-11-03
base: 1,250.00
vat_21: 262.50
total: 1,512.50
supplier_in_odoo: ok
duplicate: no
lines_sum = total: ok
purchase_order: P00218 (match)
result: ready for draft
odoo: account.move (in_invoice)
status: draft
suggested account: 600000
attachment: FAC-2026-0412.pdf
id: 4812
exception: amount over threshold
notification: Teams, Purchasing channel
action: approved by manager
log: n8n execution 18233
today: 37 received
in draft: 33
exceptions: 4 (see link)
workflow errors: 0
Step 1 of 6

The invoice arrives in the mailbox

The workflow starts with each new email in the invoice mailbox (Gmail, Outlook or any IMAP mailbox). It discards anything that is not an invoice, such as advertising or notices, and separates each attached PDF. If a supplier sends a link instead of an attachment, n8n downloads the document.

Step 2 of 6

AI extracts the invoice data

An AI model reads the PDF, no matter how each supplier designs it, and returns structured data: supplier and tax ID, number and date, due date, tax base, VAT rates, withholdings and lines. If the document is a scanned image, the text is recognized first. The model can run in the cloud or locally, so the invoice never leaves the company.

Step 3 of 6

Checks are run before posting

The workflow applies the rules that used to live in someone’s head: the tax ID must exist as a supplier in Odoo, the invoice must not already be posted, the totals must add up, and it must match a purchase order and its receipt where applicable. Anything that fails a rule is flagged as an exception, with the reason.

Step 4 of 6

The invoice is saved as a draft in Odoo

Using the Odoo node or its API, n8n creates the supplier bill as a draft, with its lines, taxes, the suggested accounting or analytic account based on the supplier’s history, and the original PDF attached. It does not validate anything on its own: the accounting stays in your team’s hands.

Step 5 of 6

A person approves what matters

Standard invoices wait for the usual validation in Odoo. Those above a given amount or flagged with an exception reach the manager by email, Teams or Slack with buttons to approve or reject, and the decision is recorded in the workflow execution.

Step 6 of 6

Tracking and alerts

Every morning, the accounting team receives a summary: invoices received, saved as drafts and pending review, with a direct link to each one. If an execution fails, the error workflow sends an alert immediately so nothing falls through the cracks.

Applications involved

Application Role in the workflow
Gmail, Outlook or IMAP Inbox for incoming invoices and trigger of the workflow.
AI model (cloud or local) Reads the PDF and extracts the data into a structured format.
Odoo Accounting and Purchase Suppliers, purchase orders, receipts and the draft invoice with its attachment.
Microsoft Teams, Slack or email Exception alerts and one-click approval.
Google Drive or SharePoint Optional PDF archive by supplier and year.

Using other applications? n8n has more than 2,000 integrations and connects with any software that has an API. We cover this in n8n integrations.

Already using Odoo? We also have our own product for this inside Odoo: AI-powered supplier invoice reading. With n8n we take it further when invoices come from several mailboxes, supplier portals or other ERPs.

Variations of the same use case

Other ERPs

The same workflow posts to other ERPs with an API, or to an intermediate spreadsheet if the ERP does not have one.

Supplier portals

For suppliers that publish their invoices on a portal, n8n downloads them periodically or is combined with an RPA robot.

Electronic invoicing

When the invoice arrives in a structured format (Facturae or UBL), it is read directly without AI, which is faster and leaves no margin for error.

Expenses and receipts

With the same idea, photos of receipts are turned into expense reports ready for approval.

Control, security and human in the loop

  • Nothing is posted automatically: invoices are saved as drafts and validation remains with your team.
  • Traceability: each invoice links to the n8n execution that created it, with the data read and the rules applied.
  • Data stays in-house: with n8n on your own server and a local AI model, documents never leave the company.
  • Minimum permissions: the workflow’s Odoo user can only create draft invoices.
  • Error alerts: if something fails, an alert is sent and the email goes back to the queue.

What we measure to know it works

Before we start, we take a snapshot of the current process and, once the pilot is running, we compare:

  • Average time from the invoice’s arrival until it is in Odoo.
  • Percentage of invoices that go through without manual correction.
  • Errors detected (duplicates, amounts that do not add up) before payment.
  • Administration hours freed up per month.

How we implement it

  1. Process assessment. Volume, applications, common exceptions and who approves what.
  2. Workflow design in n8n together with you, with the business rules documented in writing.
  3. Pilot in a controlled production environment, with human review of everything at the start.
  4. Go-live with error alerts, secure credentials and documentation.
  5. Maintenance and training so your team understands and can adjust the workflow.

Frequently asked questions

Can supplier invoices be automated with n8n?

Yes. n8n collects the invoices from email, an AI extracts the data even when each supplier uses a different format, validations are applied, and the invoice is saved as a draft in Odoo or another ERP with the PDF attached.

Does the AI get every invoice right?

Accuracy is high with standard invoices, but nothing is taken for granted: the checks on tax IDs, totals, duplicates and purchase orders catch anything that does not add up and send it for review. That is why invoices are saved as drafts.

Do my invoices leave the company?

They do not have to. n8n can be installed on your own server and the reading can be done by a local AI model. If a cloud model is used, we choose providers and configurations that comply with the GDPR.

Does it work with ERPs other than Odoo?

Yes, with any ERP that has an API. If it does not, n8n can leave the data in an import format or be combined with an RPA robot.

How long does it take to get it up and running?

It depends on the volume, the number of mailboxes and the validation rules. We start with a pilot on one mailbox and a few specific suppliers, and expand it once the results have been measured.

How many supplier invoices do you type in every month?

Tell us how they reach you and which ERP you post them in, and we will show you what the workflow would look like.

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