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Guernsey TIN number guide

Social Insurance number​

Social Insurance number is issued only to individuals at birth or on attaining recidency by the Guernsey Revenue Service. It also performs the equivalent function of a tax identification number.

Consisting of six digits preceded by GY, such as GYXXXXXX (where 'X' represents a digit from 0 to 9), the Tax Identification Number (TIN) format in Grenada is a vital element for tax identification purposes. The numbers are usually issued sequentially.

In certain instances, primarily before 1979 and the digitization of records, individuals relocating permanently to Guernsey from the UK or Jersey were granted permission to keep their original UK/Jersey Insurance Numbers. Although this category is quite small, Financial Institutions should recognize it as a potentially legitimate Tax Identification Number (TIN) for Guernsey-related purposes

UK National Insurance Number (NINO)​

A UK National Insurance Number (NINO) consists of two letters, followed by six numbers, and concludes with a final letter, always being A, B, C, or D. For instance, the format is QQ 12 34 56 A.

Jersey Social Security Number​

A Jersey Social Security Number is composed of six digits preceded by "JY" and concludes with a final letter. For example, the format is JY 123456 A

Company Registration Number​

For businesses registered in Guernsey, the Tax Identification Number (TIN) corresponds to the Company Registration Number provided by the Guernsey Registry. These registration numbers commence from "1" and progress sequentially. The number itself ranges from one to six digits, such as X to XXXXXX, where X denotes a digit between 0 and 9.

Official database - Company Search

Foreign Entities For companies with tax residency in Guernsey but not incorporated locally, the Tax Identification Number (TIN) is the Guernsey tax reference number issued by the Guernsey Revenue Service. The TIN format typically consists of a single digit followed by a letter and then six digits. In many cases, there may be an additional letter suffix, exemplified as 1C 123456 / O.

Partnerships Registered in Guernsey: For partnerships formed and registered in Guernsey, the Tax Identification Number (TIN) corresponds to the Partnership Registration Number issued by the Guernsey Registry. You can find more details on the Guernsey Registry website.

Partnerships Registered Outside of Guernsey: In the case of partnerships registered outside of Guernsey but tax-resident in the jurisdiction due to effective management, the TIN is the Tax Reference Number (TRN) issued by the Guernsey Revenue Service. The TRN format typically includes a single digit followed by two letters and then six digits. It may also be followed by a letter suffix, for instance, 1PP 123456 / F.

Foundations: For Guernsey Foundations, the TIN is the Foundation Registration Number provided by the Guernsey Foundations Registrar. Registration numbers commence at "1" and increase sequentially. The number is a concise sequence of one to three digits, such as X, XX, or XXX, where X represents a number between 0 and 9.

Charities: The TIN for Guernsey Charities is the registration number issued by the Guernsey Charities Register. The charity registration number consists of one to three digits following the prefix 'CH' (i.e., CHX, CHXX, CHXXX).

Non-Profit Organizations (NPO): Non-Profit Organization registration numbers consist of one to three digits following the prefix "NP" (i.e., NPX, NPXX, NPXXX).

Trusts: Guernsey resident trusts do not receive Tax Identification Numbers (TINs) or functional equivalents. For Guernsey Trusts, the TIN should be reported as "NOTIN."

Frequently Asked Questions​

My employer is based outside Guernsey — do they have to register for ETI and pay social security contributions?​

Non-Guernsey businesses have no legal obligation to register for the Employees' Tax Instalment (ETI) scheme or to pay the employer share of social security contributions. However, if your overseas employer does not pay the secondary (employer) share of social security contributions, this directly damages your personal contribution record and can reduce your entitlement to the state pension and other benefits. The Revenue Service cannot enforce payment from a non-Guernsey employer. The recommended workaround is for you, as the Guernsey-resident employee, to operate the payroll yourself and remit contributions under a formal agreement with your employer. [1]

Guernsey switched to independent taxation in 2023 — why did my tax reference number change?​

Before 1 January 2023, married couples and civil partners shared a single tax reference number and filed a joint return, with the lead taxpayer (typically the older or male spouse) responsible for the couple's affairs. From 2023, independent taxation means every individual is assessed separately, with their own TRP number. Approximately 12,000 spouses who had previously shared a partner's TRP received a new individual reference number ahead of the change. The 2022 return was the last joint return; from the 2023 tax year each person must file individually. Unused allowances can still transfer between spouses automatically when assessments are finalised, but both returns must be submitted before this can happen. [2]

What is the penalty for filing a Guernsey income tax return late?​

Penalties are applied automatically if a return is not received by the deadline. The initial penalty is GBP 100, followed by a continuing daily penalty of GBP 10 for every day the return remains outstanding. For taxpayers whose income falls below the personal allowance, the total penalty is capped at GBP 50 once the return is eventually submitted. The standard annual filing deadline for personal and corporate returns is 30 November (reinstated from the 2025 year of charge onwards; the 2024 return deadline was extended to 31 January 2026). Penalties can only be appealed within 30 days of the penalty order, and the Revenue Service Tribunal accepts appeals on grounds such as a life-threatening illness that genuinely prevented filing. [3]

Does Guernsey's 0% corporate tax rate still apply given the new Pillar Two rules from 2025?​

The standard 0% corporate income tax rate is unchanged for most Guernsey companies. However, two groups face higher rates. Companies earning income from Guernsey Financial Services Commission-regulated activities (banking, insurance, fiduciary services, fund administration, and related compliance activities) pay 10% on that income; large retail businesses with taxable profits above GBP 500,000 and income from Guernsey land or property are taxed at 20%. From 1 January 2025, Guernsey also implemented a Qualified Domestic Top-up Tax (QDMTT) under the OECD Pillar Two rules: MNE groups with consolidated annual revenues of EUR 750 million or more must appoint a Domestic Filing Entity and register with the Revenue Service — failure to register can result in penalties of up to GBP 20,000 — and their effective tax rate in Guernsey is brought to 15%. [4] [5]

Does living in an Open Market property in Guernsey count toward Local Market residential qualification?​

No. Time spent living in an Open Market property does not accrue toward Local Market residential qualification. Under the Population Management Law, Local Market qualification is built through time spent in Local Market accommodation — typically 8 consecutive years to reach Established Resident status. Open Market residents can live and work in Guernsey indefinitely, but they remain restricted to Open Market housing unless they already hold a Local Market certificate. This distinction also affects the tax cap: new Open Market residents who pay GBP 60,000 or more in document duty on a Part A Open Market property can qualify for a reduced annual tax cap of GBP 60,000 for four years (in place of the standard GBP 160,000 cap on non-Guernsey source income), but paying this cap does not accelerate access to Local Market housing. [6] [7]

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