## Documentation Index Access the complete documentation index at: https://www.zoho.com/us/books/kb/llms.txt Use this file to discover all available documentation pages before proceeding. # Form W-9 * [What is Form W-9?](/ca/books/kb/form-w9/what-is-form-w9.html) * [When is Form W-9 used?](/ca/books/kb/form-w9/when-is-form-w9-used.html) * [Who needs a Form W-9?](/ca/books/kb/form-w9/who-needs-a-form-w9.html)