A foreign tax ID number, or FTIN, is the tax identification number that a non-US government assigns to its residents, the way the Social Security Administration issues SSNs or the IRS issues EINs. If you’re a foreign person receiving US-source income, or a US taxpayer with accounts abroad, this number is what links you to a foreign tax system on IRS paperwork. Leaving it off a form you were supposed to complete can flip a treaty-reduced withholding rate into the full 30% statutory rate, or trigger information-return penalties that start at $10,000.
What an FTIN Actually Is
Every country that collects taxes needs a way to identify its taxpayers, and the FTIN is whatever number the foreign government uses for that job. The name varies. The UK calls it a Unique Taxpayer Reference. Australia uses a Tax File Number. Canada issues a Social Insurance Number or, for non-residents, an Individual Tax Number. Many countries simply call it a Taxpayer Identification Number. Format and length differ, because each country designs its own system.
No US agency issues, standardizes, or maintains a directory of FTINs. You can’t look one up on an IRS page the way you’d verify an EIN. The structure depends entirely on the foreign jurisdiction.
Don’t confuse an FTIN with an ITIN. An ITIN is issued by the IRS to people who need a US tax ID but can’t get an SSN. An FTIN is issued by a foreign government under its own laws. A nonresident alien may hold both: an ITIN for US filing purposes and an FTIN from their home country.
When Foreign Payees Need an FTIN: W-8 Forms and the 30% Rate
Federal law imposes a default 30% withholding tax on most US-source income paid to foreign persons, including dividends, interest, royalties, and certain other payments.1Office of the Law Revision Counsel. 26 USC 1441 – Withholding of Tax on Nonresident Aliens US income tax treaties often reduce that rate, sometimes to zero, but the payee has to establish residency in the treaty country. The FTIN is how they do it.
Form W-8BEN (Individuals)
Foreign individuals use Form W-8BEN to certify non-US status and claim treaty benefits. The FTIN goes on Line 6a. The IRS requires the FTIN when the form documents an account held at a US office of a financial institution and the account holder receives US-source income reportable on Form 1042-S. Two exceptions: residents of a US territory don’t need to provide one, and neither do residents of jurisdictions on the IRS’s official list of countries that don’t issue TINs. Line 6b lets the individual state they’re not legally required to obtain one from their jurisdiction of residence.2Internal Revenue Service. Instructions for Form W-8BEN
Form W-8BEN-E (Entities)
Foreign entities use Form W-8BEN-E. The FTIN goes on Line 9b. An entity claiming treaty benefits can supply either a US TIN on Line 8 or an FTIN on Line 9b. If the entity’s jurisdiction doesn’t issue FTINs, or doesn’t legally require the entity to have one, Line 9c is checked instead.3Internal Revenue Service. Instructions for Form W-8BEN-E
A missing FTIN on a form that required one doesn’t just leave a gap. It can invalidate the treaty claim, and the withholding agent has to apply the full 30% rate.
When US Taxpayers Encounter FTINs: FBAR and Form 8938
FBAR (FinCEN Form 114)
US persons with a financial interest in or signature authority over foreign accounts exceeding $10,000 in aggregate value at any point during the year must file a Report of Foreign Bank and Financial Accounts. The form collects taxpayer identification numbers for filers and joint owners, and foreign TINs are one accepted type. If the filer doesn’t have a US taxpayer identification number, the FBAR asks for identity verification through a passport, foreign TIN, or other official document.4Financial Crimes Enforcement Network. BSA Electronic Filing Requirements For Report of Foreign Bank and Financial Accounts (FinCEN Form 114)
Form 8938
US taxpayers with specified foreign financial assets above certain thresholds file Form 8938 with their income tax return. Thresholds depend on filing status and residence. Unmarried taxpayers living in the US file when assets exceed $50,000 on the last day of the tax year or $75,000 at any point during it. Joint filers in the US: $100,000 and $150,000. Taxpayers living abroad face higher thresholds: $200,000/$300,000 for single filers, $400,000/$600,000 for joint.5Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets
One point worth flagging, because it trips people up: Form 8938 asks for the Global Intermediary Identification Number (GIIN) of your foreign financial institution, not its FTIN. The GIIN is a FATCA-specific number the IRS assigns to foreign institutions when they register. You won’t be penalized for a wrong or blank GIIN, though supplying it may reduce the chance of IRS follow-up.6Internal Revenue Service. Instructions for Form 8938
Countries That Don’t Issue TINs
Some jurisdictions simply don’t assign tax identification numbers to residents. The IRS publishes an official list, and withholding agents aren’t required to collect an FTIN from account holders residing in those places.7Internal Revenue Service. List of Jurisdictions That Do Not Issue Foreign TINs The exception originated with IRS Notice 2017-46, which initially named Bermuda, the British Virgin Islands, and the Cayman Islands. Notice 2018-20 expanded the list to include jurisdictions whose domestic laws restrict collection or disclosure of resident TINs and that request an exemption from the US competent authority.
The distinction matters when a withholding agent evaluates whether a W-8 is complete. If the payee’s country is on the list, a missing FTIN doesn’t invalidate the form. If the country issues TINs and the payee just didn’t provide one, the form may be treated as incomplete.
How to Get an FTIN
Only the foreign government where a person is tax-resident can issue an FTIN. Someone who needs one applies directly to that country’s revenue authority. The process varies, but it usually involves establishing some form of tax residency and presenting identity documents such as a passport, proof of address, and sometimes a declaration of intent to reside or conduct business there.
In many EU countries, registering with the local municipality or tax office on arrival generates a national identification number that doubles as the FTIN. Elsewhere, expect a longer wait. A non-resident applying to the Canada Revenue Agency for an Individual Tax Number should plan on six to eight weeks. Current identity documents showing name, date of birth, and photograph are required, and any documents not in English or French must include an official translation by a certified translator.8Canada.ca. Applying for an Individual Tax Number (ITN)
A US withholding agent who needs a foreign payee’s FTIN should direct the payee to their home country’s tax authority. A driver’s license, national health ID, or other non-tax identifier won’t satisfy IRS requirements unless it doubles as the country’s official tax identification number.
How to Check That an FTIN Looks Right
There’s no universal validator, because each country designs its own numbering system. The European Commission does operate a TIN online check module for EU member states. The tool confirms whether the structure or algorithm of a given TIN matches a specific country’s format. It doesn’t confirm identity or verify that the number actually exists in that country’s database; it only checks the format. It covers natural persons only, so legal entities need to be verified through other channels.9Taxation and Customs Union. Taxpayer Identification Number (TIN)
For countries outside the EU, the OECD’s Automatic Exchange Portal publishes TIN structures and sample documents for many participating jurisdictions. Withholding agents who repeatedly collect FTINs from the same countries should keep a reference sheet of expected formats, which catches obvious data-entry errors before they become compliance problems.
Penalties When an FTIN Is Missing or Wrong
Withholding Agents
When a withholding agent doesn’t have a valid W-8, the IRS presumption rules apply. For payments subject to chapter 3 (nonresident alien) withholding, the agent applies the full 30% statutory rate with no treaty reduction.10Internal Revenue Service. Instructions for the Requester of Forms W-8BEN, W-8BEN-E, W-8ECI, W-8EXP, and W-8IMY The agent is liable for any tax that should have been withheld.
FBAR
FBAR violations carry separate penalties administered by FinCEN, not the IRS. The statutory cap for a non-willful violation is $10,000 per report, adjusted annually for inflation.11Office of the Law Revision Counsel. 31 USC 5321 – Civil Penalties After the Supreme Court’s 2023 decision in Bittner v. United States, non-willful penalties apply per report, not per unreported account. Willful violations can reach the greater of $100,000 or 50% of the account balance at the time of the violation, and criminal prosecution is possible.12Financial Crimes Enforcement Network. BSA Electronic Filing Requirements For Report of Foreign Bank and Financial Accounts (FinCEN Form 114) – Section: Penalties
Form 8938
Failing to file a complete and correct Form 8938 by the due date triggers an initial $10,000 penalty. If you still haven’t filed 90 days after the IRS sends you a notice, another $10,000 accrues for each 30-day period of continued noncompliance, up to an additional $50,000. Total potential exposure for a single year: $60,000.13Internal Revenue Service. Instructions for Form 8938 – Section: Penalties
Reasonable Cause Relief
Penalties aren’t automatic. The IRS evaluates reasonable cause on a case-by-case basis, weighing whether you exercised ordinary care and were still unable to comply. For information return penalties, which cover the kind of reporting where FTINs are required, the agency applies a two-part test. First, you must show you acted responsibly by requesting extensions when available, taking steps to prevent foreseeable failures, and correcting problems as quickly as possible. Second, you must show mitigating factors or events beyond your control, such as being a first-time filer of the particular form, having a good compliance history, or actions by the IRS or another person that contributed to the failure.14Internal Revenue Service.