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:

Pull invoices ready to be sent from Airtable.
Retrieve client details and invoice items from Airtable.
Generate a professional invoice PDF using CustomJS Invoice Generator.
Send the completed invoice via email to the client.
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: info@yourcomp.org
    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