IEIM402040 - Reportable Information: Tax Identification Number CRS
Source: gov.uk (2025-11-12)


Reportable Information: Tax Identification Number CRS

The taxpayer identification number (TIN) is the unique identifier assigned to the Account Holder by the tax administration in the Account Holder’s jurisdiction of tax residence. It is a unique combination of letters and/or numbers used to identify an individual or entity for the purposes of administering the tax laws of that jurisdiction.

Any identifier assigned by a jurisdiction of source, for example, for identifying a person whose income has been subject to withholding tax at source, should not be reported.

Some jurisdictions do not issue a TIN and where that is the case there will be nothing to report unless they use other high integrity numbers with an equivalent level of identification. For individuals these include:
- Social security number
- National insurance number
- Citizen or personal identification code or number
- Resident registration number
For entities, jurisdictions may use a business/company registration code or number where no TIN has been issued.

Some jurisdictions that issue TINs have domestic law that does not require the collection of the TIN for domestic reporting purposes, Australia for example. In such cases the Reporting Financial Institution is not required to collect the TIN for those jurisdictions.

There are also limited circumstances in which residents of some jurisdictions that do issue TINs may nevertheless not have a TIN, for example individuals who have never worked in the jurisdiction and have never been provided with a TIN, and individuals who have moved to the jurisdiction and may not receive a TIN for several years after moving.

Information on the structure and form of TINs used by tax administrations, including those where domestic collection of the TIN is not required, has been published on the OECD website (http://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/#d.en.xx-xxxx-xxxx).

The TIN, or TIN equivalent, must be reported for all new accounts [see IEIM403140] where issued.

For pre-existing accounts [see IEIM402640] the TIN is reportable to the extent that it is already held in records maintained by the Reporting Financial Institution [see IEIM402300] or the Reporting Financial Institution is otherwise obliged to collect it.

For the CRS, where the TIN is not held in respect of pre-existing accounts the Reporting Financial Institution must use reasonable efforts to obtain it [see IEIM402320] by the end of the second calendar year following the year in which the accounts are identified as Reportable Accounts [see IEIM401520].

From 1 January 2026, Reporting Financial Institutions must also use reasonable efforts to obtainthe TIN in respect of a reportable pre-existing account whenever they are required to update information relating to the account under AML/KYC procedures.

Not all jurisdictions issue a TIN, or functional equivalent, to all individuals or entities; where a TIN has not been issued to an individual or entity there is an exception from the requirement to report a TIN. If and when a jurisdiction starts issuing TINs the exception no longer applies and the TIN would be required to be reported if the Financial Institution obtains a self-certification that contains such a TIN, or otherwise obtains such a TIN.

Where the reason for a missing TIN is that the Account Holder or Controlling Person is resident in a jurisdiction that does not issue TINs, no further outreach is required until there is a change in circumstances.

As Reportable Persons may be resident in more than one jurisdiction they may have two or more TINs that the Financial Institution must report.

United Kingdom

For most individuals in the UK the TIN will be their National Insurance Number.

Crown Dependencies and Overseas Territories

For Gibraltar the identifier to be reported for individuals is a social security number.

For Guernsey the identifier to be reported for individuals is a social security number.

For the Isle of Man the identifier to be reported for individuals is a national insurance number.

For Jersey the identifier to be reported for individuals is a social security number.

For guidance on reporting US TINs for FATCA purposes, see IEIM402045 (https://www.gov.uk/hmrc-internal-manuals/international-exchange-of-information/ieim402045).