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Tax & Compliance
Tax ID Number
Definition
A unique number issued by tax authorities to identify a business or individual for tax purposes.
Overview
Tax ID numbers (EIN, TIN, ABN, VAT number, etc.) are used for tax filing, invoicing, and business transactions. Format and name vary by country.
Example
In the US, businesses use an EIN (e.g., 12-3456789). In Australia, it's an ABN (e.g., 12 345 678 901).
Best Practices
Include your tax ID on invoices, contracts, and tax documents. Verify client tax IDs when required.
Common Mistakes to Avoid
Missing from invoices
Using wrong number type
Not verifying client numbers
Frequently Asked Questions
Where do I get a tax ID?
Apply through your country's tax authority—IRS in US, ATO in Australia, HMRC in UK, etc.