A foreign tax identifying number, often shortened to FTIN, is the identification number that your country of tax residence assigns to you for tax purposes. It’s that country’s equivalent of a U.S. Social Security Number or Employer Identification Number, and U.S. payers, the IRS, and foreign banks ask for it so they can match your income and accounts to the right person in the right tax system.
The word “foreign” is about perspective. A French citizen giving their French tax number to a U.S. brokerage is providing an FTIN. An American giving a Social Security Number to a bank in London is doing the same thing from the British bank’s point of view. Whichever number your home tax authority uses to identify you is your FTIN when someone in another country asks.
Which Number Counts as Your FTIN
There is no universal format. Each country structures and names its tax identifier differently, and some countries use a single national number that doubles as a tax ID while others issue a separate one purely for tax.
- United Kingdom: most individuals use their National Insurance Number (NINO); businesses and the self-employed may also have a Unique Taxpayer Reference (UTR).1GOV.UK. IEIM402040 – Reportable Information: Tax Identification Number CRS – HMRC Internal Manual
- India: the Permanent Account Number (PAN), a ten-character alphanumeric code issued by the Income Tax Department.
- Canada: the Social Insurance Number (SIN) for individuals, and a Business Number (BN) for businesses.
- Germany: the Steuerliche Identifikationsnummer, an 11-digit number assigned at birth or upon registration.
The name matters less than the function. When a bank or the IRS asks for your FTIN, they want whatever number your country uses to identify you for tax purposes. If you’re not sure which one qualifies, check your national tax authority’s website. The OECD also maintains a public portal with country-by-country details on TIN formats and issuing authorities.
Where You’ll Be Asked to Provide It
Two situations account for most FTIN requests: opening or maintaining a financial account abroad, and submitting a Form W-8 to a U.S. payer.
Banks, brokerages, and insurers around the world now collect FTINs as part of account opening. The two frameworks driving this are FATCA, the U.S. law that requires foreign financial institutions to identify and report U.S. account holders to the IRS, and the Common Reporting Standard (CRS), the OECD-backed automatic exchange of financial account information among more than 100 jurisdictions. FATCA looks at citizenship and U.S. person status; CRS looks at tax residence and runs in both directions between participating countries. Both rely on the FTIN to tie an account back to a specific person in a specific tax system.2Internal Revenue Service. FATCA Information for Foreign Financial Institutions and Entities
Form W-8BEN for Individuals
If you’re a nonresident alien receiving U.S.-source income, Form W-8BEN establishes your foreign status for withholding. Your FTIN goes on line 6a. This is especially important if you’re claiming a reduced withholding rate under an income tax treaty between your country and the United States. To claim treaty benefits, you generally need either your FTIN on line 6a or a U.S. taxpayer identification number, such as an ITIN, on line 5.3Internal Revenue Service. Instructions for Form W-8BEN
Form W-8BEN-E for Entities
Foreign entities use Form W-8BEN-E instead. An entity documenting itself as an account holder at a U.S. financial institution must enter its FTIN on line 9b if it receives U.S.-source income reportable on Form 1042-S. Exceptions apply for governments, residents of U.S. territories, and entities in jurisdictions that appear on the IRS list of countries that don’t issue FTINs. If the entity simply isn’t legally required to obtain a number, it can check line 9c to explain the omission.4Internal Revenue Service. Instructions for Form W-8BEN-E
What Happens If You Don’t Provide One
The most immediate cost is money. Without a valid FTIN (or a U.S. TIN) on your W-8BEN or W-8BEN-E, the withholding agent generally applies the statutory 30% withholding rate on U.S.-source payments such as dividends, interest, and royalties. If your treaty rate would have been 15% or 0%, that difference comes straight out of every payment. You can sometimes recover the excess by filing a U.S. tax return, but the simpler path is to get the form right the first time.3Internal Revenue Service. Instructions for Form W-8BEN
Foreign financial institutions collecting information under FATCA and CRS may also restrict account functionality or delay account opening when a required FTIN is missing. The IRS has clarified that a missing U.S. TIN alone should not automatically result in a foreign bank closing an American’s account; the agency looks at the circumstances, including what the institution did to obtain the number, and gives the institution at least 18 months to correct the issue before taking further action.
A separate set of consequences applies to U.S. persons with foreign financial assets, and it’s worth flagging because searches on FTINs often shade into this territory. If you’re required to file Form 8938 (Statement of Specified Foreign Financial Assets) and don’t, the penalty starts at $10,000. If you still haven’t filed 90 days after the IRS sends a notice, an additional $10,000 accrues for every 30-day period the failure continues, up to $50,000 in additional penalties. Reasonable cause can eliminate the penalty, but the regulation is explicit that fear of foreign-country reprisal for disclosure does not qualify. Willful failures can trigger criminal penalties under separate provisions of federal law.5eCFR. 26 CFR 1.6038D-8 – Penalties for Failure to Disclose
When You Aren’t Required to Have One
Not every jurisdiction issues tax identification numbers. Some don’t operate an income tax system that requires one; others use alternative identification methods. The IRS publishes an official list of jurisdictions that do not issue foreign TINs. If your country of residence is on that list, a withholding agent cannot require you to produce one. As of the most recent list, jurisdictions that don’t issue FTINs include Bermuda, the British Virgin Islands, and the Cayman Islands, among others.6Internal Revenue Service. List of Jurisdictions That Do Not Issue Foreign TINs
Even if your country isn’t on that list, you may still be exempt if your jurisdiction doesn’t legally require you to obtain a tax ID. On Form W-8BEN, you can check the box on line 6b to indicate this, which the IRS treats as an adequate explanation for the missing number.3Internal Revenue Service. Instructions for Form W-8BEN
How to Get One
The process varies by country, but the starting point is always the tax authority where you’re a resident. Most national tax agencies have an online portal for applying for or looking up your existing number. In some countries the number is assigned automatically at birth or on registering as a resident, so you may already have one without knowing it.
If you live abroad and can’t easily reach the local tax office, your country’s embassy or consulate may be able to point you in the right direction. For situations involving multiple residencies, dual citizenship, or business structures, a local tax advisor familiar with that country’s system is usually worth the cost. Financial institutions will reject incomplete W-8 forms, and resubmitting means delays that can hold up payments or account access.