What Is a Tax Identification Number (TIN)?
A Tax Identification Number (TIN) is an administrative identifier which a tax authority assigns to individuals or entities, under formats set by national law.
Also known as: TIN, Taxpayer Identification Number.
How Tax Identification Number (TIN) works
A Tax Identification Number (TIN) is the reference a tax authority uses to match returns, payments and third-party reports to a single taxpayer, and the number generally follows the person or entity across filings, payroll, bank onboarding and cross-border reporting. In the United States, the IRS describes a TIN as a number used in administering tax laws, issued by the Social Security Administration for an SSN and by the IRS for the EIN, ITIN, ATIN and PTIN. Under Directive 2014/107/EU, financial institutions report each reportable person's name, address, Member State of residence and TIN, although no TIN is required where the residence jurisdiction does not issue one. Formats, issuance conditions and obligations to provide a TIN vary by country and remain subject to local rules.
Tax Identification Number (TIN) vs VAT Identification Number
Unlike a VAT identification number, which identifies a business registered for value added tax, a Tax Identification Number (TIN) identifies a taxpayer for income tax and general reporting, although some countries use one number for both.
Example
Illustrative example: A freelancer resident in Country A opens a bank account in Country B. The bank requests a self-certification with the Country A TIN and reports the balance and TIN to Country B's tax authority, which forwards the data to Country A under automatic exchange.
Common misconception
Myth: A passport number can replace a TIN on bank tax self-certification forms.
Reality: A passport number is an identity document reference rather than a Tax Identification Number, and financial institutions generally request the TIN issued by each country of tax residence unless that country issues none.
Frequently asked questions
What is a TIN number?
A Tax Identification Number (TIN) is an identifier which a tax authority assigns to an individual or entity so returns, payments and third-party reports can be matched to the correct taxpayer.
Do banks need a TIN from a foreign customer?
Banks applying the Common Reporting Standard generally collect the Tax Identification Number of each country of residence, because Directive 2014/107/EU requires reporting the TIN unless the residence jurisdiction does not issue one.
Related terms
- VAT Identification Number — Separate number used for VAT registration
- Individual Taxpayer Identification Number (ITIN) — US TIN for individuals ineligible for an SSN
- EIN (Employer Identification Number) — US TIN identifying business entities
- Form W-8BEN — US form where foreign TINs are declared
Related guides
- Spain NIE guide — Spanish identification number for foreigners
- Accounting and bookkeeping for digital nomads — Administrative records nomads keep across countries
Sources
Last verified: 2026-10-09. This entry is general information, not tax or legal advice; rules vary by country and change over time.
