Automated PDF Form Filling for W-9 and More with PDF.co

🧑‍💻 Description This workflow demonstrates how to take structured data (e.g., Name, Business, Address) and automatically fill a PDF form (IRS W-9) using PDF.co inside n8n.

The workflow extracts values from a data source (e.g., Set node, database, or webhook), maps those values to fields in a PDF template, and generates a completed PDF. This can be adapted for contracts, invoices, HR forms, or any standardized documents that need automation.

By chaining additional nodes, you can also store completed PDFs in Google Drive/Dropbox, email them to recipients, or route them into CRM/ERP systems.

Disclaimer: this template can only be used on self-hosted n8n instances

⚙️ Setup Instructions

1️⃣ Prepare Your Data Add a Set node (or connect to your data source such as Google Sheets, Airtable, or a webhook).
Define fields like:
Name
Business
Address
CityState
These fields will map directly to form fields in the PDF.

2️⃣ Connect PDF.co Create a free account at PDF.co
Copy your API Key from the dashboard
In n8n → Credentials → New → PDF.co API
Paste your API Key → Save
In the PDF.co node, select your credential and choose the Fill a PDF Form operation
Map each field in your dataset to the corresponding PDF form field (e.g., Name → Line 1 on the W-9).

📄 Example Form This template uses the official IRS W-9 PDF:
https://www.irs.gov/pub/irs-pdf/fw9.pdf

Mapped fields include:
Name → Line 1
Business → Line 2
Address + City/State → Address block

You can expand this by mapping additional fields such as Tax Classification, Exemptions, TIN, and Signature.

🎛️ Customization Guidance Different PDFs**: Swap the W-9 for any contract, invoice, or onboarding form your business uses.
Dynamic Data Sources**: Replace the Set node with Google Sheets, Airtable, or API/Webhook inputs to pull live data.
Automated Delivery**: After filling the form, use Email or Slack nodes to send PDFs directly to recipients.
Document Storage**: Save completed PDFs automatically to Google Drive, Dropbox, or AWS S3.
Bulk Processing**: Loop through rows of a dataset (e.g., customer list) to generate multiple personalized PDFs at once.

📬 Contact Need help customizing this workflow for contracts, invoices, or HR forms?

📧 robert@ynteractive.com
🔗 Robert Breen
🌐 ynteractive.com