Automatic invoice generation and email with Airtable and CustomJS PDF generator

> ⚠️ Notice:
> This workflow uses the CustomJS Invoice Generator node from customjs.space, which requires a self-hosted n8n instance and a CustomJS API key.

Google Spreadsheet → Invoice Generation → Email Workflow

This workflow demonstrates how to:

1. Pull invoices ready to be sent from Airtable.
2. Retrieve client details and invoice items from Airtable.
3. Generate a professional invoice PDF using CustomJS Invoice Generator.
4. Send the completed invoice via email to the client.
5. Update the invoice status in Airtable automatically.

Public Airtable Example

Workflow Overview

1. Trigger Workflow

• Node: When clicking ‘Execute workflow’ (Manual Trigger)
• Starts the workflow when executed manually in n8n.

2. Get Ready Invoices

• Node: Get Ready Invoices (Airtable)
• Retrieves all invoices from Airtable where Status = 'Ready'.

3. Loop Over Items

• Node: Loop Over Items (Split In Batches)
• Processes each invoice individually.

4. Get Clients

• Node: Get Clients (Airtable)
• Fetches client details for the current invoice:
  • Name
  • Address
  • Tax ID

5. Get Invoice Items

• Node: Get Invoice Items (Airtable)
• Retrieves all items associated with the invoice and passes them for aggregation.

6. Map Fields

• Node: Map Fields (Set)
• Maps the invoice items into a structured format for the invoice generator:
  • Description
  • Quantity / Hours
  • Unit Price
  • Invoice ID

7. Aggregate

• Node: Aggregate
• Aggregates all invoice items into a single JSON array for the invoice.

8. Set Company Details

• Node: Set Company Details (Set)
• Defines issuer and payment information:
  • Company Name
  • Address
  • Tax ID
  • Email & Phone
  • Bank Details

9. Generate Invoice

• Node: Generate Invoice (CustomJS Invoice Generator)
• Generates a PDF invoice using all collected data:
  • Issuer / Company information
  • Recipient / Client information
  • Invoice items
  • Billing information (Invoice number, date, currency, tax, notes)

10. Send Email With Attachment

• Node: Send Email With Attachment (Email Send)

• Sends the generated invoice PDF to the client:

  • From: {{ $json.InvoiceEmail }}

  • To: [email protected]

  • Subject: Your Invoice for Last Month

  • Body Text:

    Hello,
    
    Please find attached your invoice for the last month. Thank you very much for your cooperation.
    
    Best regards,
    Henrik
    

• Uses SMTP credentials for sending emails.

11. Update Record

• Node: Update record (Airtable)
• Marks the invoice as Sent in Airtable.

Requirements

• Self-hosted n8n instance
• CustomJS API key
• SMTP credentials
• Airtable API key and base access