Create and send Pennylane invoices from webhook data with Slack and Gmail alerts

Description

Who is this for

SMEs and freelancers using Pennylane (the leading French accounting platform) who want to automate invoice creation from their CRM, forms, or any business tool.

What it does

This workflow receives deal or order data via a POST webhook, searches for the customer in Pennylane by email (or creates one if not found), generates a customer invoice with line items and VAT, optionally sends it by email through Pennylane, and notifies your team via Slack and/or Gmail with an HTML-formatted summary.

How to set up

Import this workflow into n8n
Create a Header Auth credential with name Authorization and value Bearer <YOUR_PENNYLANE_TOKEN>
Select your Slack channel in the SL Send Notification node
(Optional) Connect your Gmail credential for HTML email notifications
Configure invoice numbering in your Pennylane settings (required for finalized invoices)
Send a test POST request to the webhook URL with a sample payload

Requirements

Pennylane account with API access (Essentiel plan or higher)
Pennylane API token with scopes: customer_invoices:all, customers:all
(Optional) Slack workspace for team notifications
(Optional) Gmail OAuth for email notifications

How to customize

Set draft: true in the Code Build Invoice Payload node to create draft invoices for manual review before finalizing
Replace Slack/Gmail with Telegram or any other notification channel
See example payloads and CRM mappings (Pipedrive, Sellsy, Axonaut) in the GitHub repo: https://github.com/Gauthier-Huguenin/n8n-pennylane-auto-invoicing