Generate and Send PDF Invoice with n8n

26 May, 2026 7 min read

Introduction

Automation platforms like n8n are becoming increasingly popular for building internal tools, AI workflows, and business automations without writing full backend applications.

In this tutorial, we will build a complete automated workflow that:

collects invoice data from a form
generates an HTML invoice template
converts HTML to PDF using HTML2PDF.app
sends the generated PDF invoice by email

The final workflow will look like this:

Form Trigger
   ↓
Generate HTML Template
   ↓
Convert HTML to PDF
   ↓
Send Email with PDF Attachment

At the end of this article, you will also be able to download and import the complete n8n workflow template.

What We Will Build

In this example:

User opens a form
User enters:
- customer name
- email address
- invoice number
- amount
n8n generates invoice HTML dynamically
HTML is converted to PDF using HTML2PDF.app API
PDF is sent automatically by email

Step 1 — Create Form Trigger

Create a new workflow in n8n and add "Form Trigger" node.

This node creates a public form where users can submit invoice data.

Add fields:

Field	Type
customerName	Text
email	Email
invoiceNumber	Text
total	Text

Step 2 — Generate HTML Invoice Template

Add a "code" node.

This node will dynamically generate invoice HTML.

const clientName = $json.clientName;
const clientEmail = $json.clientEmail;
const invoiceNumber = $json.invoiceNumber;
const total = $json.total;

const html = `
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <style>
    body {
      font-family: Arial, sans-serif;
      padding: 40px;
      color: #333;
    }

    .invoice {
      max-width: 700px;
      margin: 0 auto;
      border: 1px solid #ddd;
      padding: 30px;
    }

    h1 {
      color: #222;
    }

    .total {
      margin-top: 30px;
      font-size: 24px;
      font-weight: bold;
    }
  </style>
</head>
<body>
  <div class="invoice">
    <h1>Invoice</h1>

    <p><strong>Invoice Number:</strong> ${invoiceNumber}</p>

    <p><strong>Customer:</strong> ${clientName}</p>

    <div class="total">
      Total: €${total}
    </div>
  </div>
</body>
</html>`;

return {
  json: {
    html,
    recipient: clientEmail,
    name: clientName
  }
};

Step 3 — Convert HTML to PDF

Now add an "HTTP Request" node.

Configuration:

Setting	Value
Method	POST
Authentication	Generic Credential Type
Generic Auth Type	Header Auth
Header Auth	Name: `x-api-key`, Value: `your-api-key-***`
URL	`https://api.html2pdf.app/v1/generate`
Send Body	On
Specify Body	Using Fields Below
Body Parameters	html: `{{$json.html}}`
Response Format	File
Put Output in Field	`data`

By setting "Header Auth" click edit on "Header Auth account" and set values accordingly to the image below. You will need an HTML2PDF.app API key — you can register and get a free API key here:

Get Free API Key

header auth account setup on n8n

We recommend storing your HTML2PDF.app API key securely using the Credentials system instead of hardcoding it into the workflow.

Step 4 — Send PDF by Email

Add a "Send Email" node.

In this tutorial we use SMTP credentials with Mailgun.

Configuration example:

Field	Value
From Email	[email protected]
To Email	`{{ $json.recipient }}`
Subject	Your Invoice
Email Format	HTML
Attachments	`data`

Example of HTML email message:

Hello {{ $json.name }},

<br><br>

Please find your invoice attached.

<br><br>

Thank you.

Testing the Workflow

When you finish all these steps, the result of your workflow should be similar to this (nodes can have custom names for clarity):

n8n workflow template

After activating the workflow:

Open the generated form URL
Enter invoice details
Submit form
Receive PDF invoice by email automatically

Conclusion

Combining n8n with HTML2PDF.app allows you to build powerful document automation workflows in minutes.

Instead of manually generating invoices, reports, or PDFs, you can fully automate the entire process:

collect data
generate HTML
convert to PDF
deliver automatically

without building a custom backend service.

Workflow Template

Download the ready-to-use n8n workflow template and import it directly into your n8n instance. After importing, configure your own HTML2PDF.app API credentials and email provider credentials.

Download Template