Invoice PDF Generator n8n: Forms → APITemplate.io, Drive, Gmail, Slack

Turn n8n Form submissions into client-ready invoice PDFs—automatically

This Invoice PDF Generator n8n workflow takes an n8n Form invoice request, generates a polished invoice PDF using APITemplate.io, uploads it to Google Drive, emails the customer via Gmail, and posts an invoice summary with links to Slack.

What this workflow does

• Receives invoice data from an n8n Form submission.
• Builds a single form_data object and verifies required fields are present (including customer name, email, and invoice number).
• Creates an invoice payload by generating a document ID and adding a predefined list of invoice line items.
• Generates the PDF from an APITemplate.io PDF template by mapping form fields and items into the template properties.
• Confirms successful PDF generation and captures the resulting binary data for upload and email.
• Uploads to Google Drive into a specified destination folder.
• Emails the invoice via Gmail with Drive and direct download links for the customer.
• Notifies a Slack channel with the invoice details and links for internal visibility.

Use cases

• SaaS operators generating invoices when customers submit requests through an n8n Form.
• Automation engineers standardizing invoice delivery with APITemplate.io, Google Drive, and Gmail.
• Teams that need an audit trail and quick internal updates via Slack every time an invoice is created.

Technical details

• APITemplate.io: PDF template ID and placeholder mapping (e.g., fullName, invoice_no, items).
• Google Drive: OAuth credentials + upload destination folder.
• Gmail: OAuth credentials to send the invoice email to the form submitter.
• Slack: OAuth credentials + target channel for invoice notifications.
• n8n nodes used: if, set, gmail, slack, sticky note, form trigger.