Definition
A tax ID is the number a tax authority assigns to a business for reporting and collecting taxes. Examples include the EIN in the United States, VAT numbers in the EU and UK, the ABN in Australia, and the GSTIN in India. Many countries require the seller's tax ID on every invoice, and the buyer's on business-to-business invoices.
Also called: Tax identification number, TIN, EIN, VAT number, ABN, GSTIN
Tax ID in practice
Including your tax ID on invoices signals legitimacy and is mandatory wherever you are registered for VAT or GST. Keep it in your business profile so it prints automatically on every document.
Frequently Asked Questions
Do I need a tax ID to send an invoice?
In the US, sole proprietors can invoice without an EIN, though many get one to avoid sharing a Social Security number. In VAT and GST countries, a registered business must show its number on tax invoices.