Offshore Disclosure: Jersey, Switzerland & US-UK Filers

An Offshore disclosure involving Jersey, Guernsey, Switzerland or Singapore accounts is never a single filing. A UK-resident US citizen sits inside two regimes simultaneously: the IRS reaches worldwide accounts through citizenship-based taxation, and HMRC reaches the same balances as offshore matters. Both submissions must be built together, from one reconciled set of facts.

This is the scenario generalist guidance handles worst. American expat firms explain the Streamlined Foreign Offshore Procedures as though the only foreign accounts a US citizen in London could hold are British ones. UK disclosure specialists explain the Worldwide Disclosure Facility as though HMRC were the only revenue authority with a claim. Neither describes what actually happens when a client walks in with a Jersey private bank relationship opened in 2011, a Swiss vested-benefits account left behind after a Zurich secondment, and a Singapore brokerage account funded from a bonus — none of it reported to either authority.

At Jungle Tax this is routine work. What follows is the technical map: what each authority already knows, which route applies on each side, and — the part almost nobody writes about — how to stop the two submissions contradicting each other.

Why do accounts outside the UK put you inside two disclosure systems at once?

The trap is a category error. Clients think of their accounts geographically: "my UK accounts" and "my offshore accounts". Both tax authorities think about them differently, and neither uses the client's mental map.

To the IRS, every account outside the United States is a foreign financial account. A Barclays current account in London and a private bank account in St Helier are the same species of problem: both are FBAR-reportable, both may be Form 8938 assets, and neither is made less reportable by the fact that the holder is also a British citizen who has lived in the UK for thirty years.

To HMRC, an account in Jersey, Zurich or Singapore held by a UK tax resident is an offshore matter — a statutory category that attracts harsher penalty treatment and longer assessment windows than the identical failure on a domestic account. The Jersey account is not merely undeclared income; it is undeclared income in an offshore territory, and UK law treats that as a distinct and more serious failing.

So the same Jersey balance is simultaneously a foreign account to the IRS and an offshore matter to HMRC. There is no jurisdiction in which it is neither. And critically, the US-UK double tax treaty does not resolve this. The treaty allocates taxing rights over income; it does not consolidate two independent disclosure and penalty regimes into one process. Nothing in it lets a submission to one authority discharge an obligation to the other.

What has already reached each authority before you file?

Clients frequently assume that because they have heard nothing, nothing has been reported. That assumption has been wrong since roughly 2017. The realistic starting position is that both authorities hold data on these accounts already, and the disclosure is a matter of getting ahead of information that has been sitting in a database.

What HMRC already holds

The Common Reporting Standard is the mechanism. Jersey, Guernsey, the Isle of Man, Switzerland, Singapore, Hong Kong, Luxembourg and the UAE all exchange financial account information automatically with the UK. A UK-resident account holder in any of these places has typically had their name, address, tax identification number, account number, year-end balance and gross payments transmitted to HMRC annually for several reporting cycles.

This is why "nudge letters" arrive. HMRC's offshore compliance teams run CRS data against Self Assessment records and write to taxpayers whose returns show no corresponding foreign income. Receiving one materially changes the position: a disclosure made afterwards is a prompted disclosure, which caps the available penalty reduction. The window for an unprompted disclosure closes the moment that letter lands.

What the IRS already holds

FATCA is the parallel mechanism, and its architecture differs by jurisdiction in a way that matters. Jersey, Guernsey, the Isle of Man and Singapore operate Model 1 intergovernmental agreements: local institutions report US-owned accounts to their own authority, which forwards the data to the IRS. Switzerland has historically operated under a Model 2 agreement, under which Swiss institutions report directly to the IRS, with aggregate reporting and group requests used to reach recalcitrant accounts — a structural difference that has produced a distinctive and long-running enforcement history for Swiss banking relationships.

The practical point for a client is the same either way: if the account was correctly identified as US-owned, the IRS has the data. If it was not — because the bank never asked, or because a British passport was presented at onboarding — the account may be invisible to the IRS while being fully visible to HMRC through CRS. That asymmetry is common and it drives the sequencing decision discussed below.

US versus UK: how the same offshore account is treated

Feature	United States (IRS)	United Kingdom (HMRC)
Basis of the claim	Citizenship and green card status — applies regardless of where you live	UK tax residence for the years in question
Principal disclosure route	Streamlined Foreign Offshore Procedures (non-willful, resident abroad)	Worldwide Disclosure Facility via the Digital Disclosure Service
Look-back period	3 years of income tax returns, 6 years of FBARs	Up to 4, 6, 12 or 20 years depending on behaviour
Core certification	Form 14653 non-willfulness statement	Behaviour classification and disclosure report
Data feed	FATCA (Model 1 or Model 2 agreements)	Common Reporting Standard
Penalty exposure if accepted	Title 26 and FBAR penalties waived under SFOP; statutory interest still due	Tax, interest and penalties payable in full; no special terms
Jurisdiction sensitivity	None — all non-US accounts treated alike	Territory categorisation raises the penalty ceiling
Currency of computation	US dollars, Treasury year-end rates for FBAR	Pounds sterling

Which US route applies?

For the profile in question — a US citizen resident in the UK who genuinely did not appreciate the reporting obligation — the Streamlined Foreign Offshore Procedures are usually the correct route. Eligibility turns on meeting the non-residency test (broadly, in one of the three most recent years for which the return due date has passed, having no US abode and being physically outside the United States for at least 330 full days) and on the failure being non-willful. The IRS sets out the full framework in its streamlined filing compliance procedures guidance and the specific terms for taxpayers abroad in its guidance for US taxpayers residing outside the United States.

The submission comprises three years of delinquent or amended returns with every required international information return attached, six years of FBARs filed electronically, payment of the resulting tax with statutory interest, and Form 14653. Where the procedures are properly used, failure-to-file, failure-to-pay, accuracy-related, information-return and FBAR penalties are not asserted.

Two variants matter. A US citizen who has moved back to the United States while still holding the Jersey or Swiss accounts falls into the Streamlined Domestic Offshore Procedures instead, which carry a miscellaneous offshore penalty calculated on the highest aggregate value of the unreported assets — a materially different economic outcome. And a taxpayer whose conduct was not genuinely non-willful should not be in the streamlined programme at all; the IRS Criminal Investigation Voluntary Disclosure Practice exists for that case, and misusing the streamlined route in willful circumstances is itself a serious exposure. Where accounts were held through a nominee, a numbered arrangement, or a structure created specifically to obscure ownership, that assessment needs to be made before anything is filed. Our IRS streamlined filing specialists make that determination first, not last.

Which UK route applies?

On the UK side the mechanism is the Worldwide Disclosure Facility, accessed through HMRC's Digital Disclosure Service. The process is documented in HMRC's guidance on how to make a disclosure using the Worldwide Disclosure Facility. In outline: notify HMRC, receive a Disclosure Reference Number, and then complete the full disclosure within 90 days, with an extension available on request in genuinely complex cases.

Three features of the WDF surprise clients who have read about earlier facilities.

• There are no special terms. The Liechtenstein and Crown Dependency facilities offered capped penalties and, in some cases, immunity from prosecution. Those closed in 2015 and 2016. The WDF offers process, not concessions: tax, interest and penalties are payable in full.
• The disclosure cannot be limited to one jurisdiction. A taxpayer disclosing a Jersey account cannot ringfence it. HMRC expects a complete disclosure of all irregularities, onshore and offshore. A partial disclosure that later proves incomplete undermines the entire submission.
• Where the money sat affects the ceiling. Under the offshore penalty regime, territories are categorised by the quality of their information exchange with the UK, with maximum penalties rising across the categories as set out in HMRC's Compliance Handbook guidance on territory categories. The applicable category is tested at the date of the failure, not today — so a long-running Swiss or Jersey account may straddle more than one categorisation across the disclosure period.

Sitting behind all of this is the Failure to Correct regime, which applies to offshore non-compliance that existed at 5 April 2017 and was not corrected by the end of the Requirement to Correct window on 30 September 2018. FTC penalties start far higher than ordinary penalties, with a standard charge expressed as a percentage of the tax and additional charges available where asset values are large or where assets were moved to frustrate discovery. For accounts opened a decade or more ago — which is most Jersey and Swiss relationships of this kind — FTC is usually in scope and is the single largest driver of the UK cost.

How do you stop the two submissions contradicting each other?

This is the heart of the matter and the reason a coordinated approach is not a luxury. Two disclosures, prepared by two firms who never speak, generate contradictions that neither authority will overlook.

The behaviour narrative must be consistent

Form 14653 requires a signed, penalty-of-perjury statement that the failure to report was non-willful — that it resulted from negligence, inadvertence, mistake, or a good-faith misunderstanding of the law. HMRC, meanwhile, requires the taxpayer to classify their own behaviour, and the categories run from a reasonable excuse, through careless, to deliberate and deliberate-and-concealed. The behaviour category drives both the penalty range and the number of years assessable.

A UK adviser optimising the UK outcome in isolation may see no harm in conceding "deliberate" to close matters efficiently. That concession is a written admission, made to a tax authority that exchanges information with the IRS, that the taxpayer knowingly failed to declare the very accounts they are simultaneously certifying they failed to report non-willfully. The two documents cannot both be right. We prepare the behaviour analysis once, apply it to both submissions, and ensure the factual narrative — when each account was opened, why, what the taxpayer understood, who advised them, what triggered the realisation — is identical in substance and consistent in wording across Form 14653 and the UK disclosure report.

The account schedule must be identical

One reconciled schedule should drive both filings: every account, its jurisdiction, opening date, closing date if applicable, ownership, signatory rights, and year-by-year peak and closing balances. It then feeds the FBAR in dollars at Treasury year-end rates, Form 8938 on its own thresholds, and the UK disclosure in sterling. An account that appears on the FBAR but not in the UK disclosure — or vice versa — is a discrepancy visible to both authorities through exchange of information.

The income figures must reconcile, even though they differ

They will differ legitimately, and the disclosure should explain why rather than pretend otherwise. A Jersey-domiciled non-reporting fund produces an offshore income gain taxed in the UK at income tax rates on disposal, while the same holding is a passive foreign investment company for US purposes with an entirely different computation and timing. Swiss and Singapore accounts generate the same divergences. The right approach is a reconciliation schedule showing the same underlying transactions producing two different tax results for two identifiable technical reasons — which reads as competence, not concealment.

Foreign tax credits have to be modelled, not assumed

Where UK tax arises on the disclosed income, it should relieve the corresponding US tax through the foreign tax credit — but the mechanics are unforgiving. Credit generally follows tax paid or accrued, so a UK disclosure settled after the US returns are filed may require a redetermination and amended US filings to claim it. Basketing matters too: passive income sits in the passive basket, and UK tax on an offshore income gain will not always find US income in the same basket and year to relieve. Modelling this before either submission goes out frequently changes the order in which they are filed.

Which disclosure should go first?

There is no universal answer, but there is a reliable framework.

• Prompted status is the first consideration. If an HMRC nudge letter has arrived, the UK clock is already running and the UK notification should be made promptly to preserve whatever penalty mitigation remains. If instead a FATCA letter has arrived from a Jersey or Swiss institution, the US side is the more urgent exposure.
• Quantum is the second. Where UK tax dominates — typically with substantial offshore income gains or large unreported interest across many years — settling the UK position first gives the US foreign tax credit computation firm numbers to work with.
• Statutory limits are the third. The UK assessment window for offshore matters extends considerably beyond the ordinary time limits, and the US position on unfiled international information returns can leave the assessment period open indefinitely for the relevant year. Neither clock is running out in your favour, which is an argument for moving on both fronts together rather than sequentially.

In practice we most often prepare both submissions in parallel from a single reconciled fact base, then release them in the order the individual case demands. Preparing them in parallel is not the same as filing them simultaneously, and the distinction matters.

What goes wrong in each jurisdiction?

Jersey, Guernsey and the Isle of Man

These are trust and structure jurisdictions, and that is where the complexity sits. A Jersey discretionary trust with a US citizen beneficiary can drag in US trust reporting obligations that carry substantial penalties in their own right and that are frequently missed by advisers focused on bank accounts. Jersey and Guernsey investment funds are typically non-reporting for UK purposes and PFICs for US purposes — a double penalty regime on the same holding. Clients also routinely misdescribe these accounts as "UK" accounts because the bank brand is British and the statements arrive in sterling. They are not UK accounts for either authority.

Switzerland

Swiss cases carry two distinctive features. The first is pension residue: vested benefits accounts and pillar 3a arrangements left behind after a Swiss assignment, which the client has stopped thinking of as an account at all but which is reportable and may be taxable. The second is insurance wrappers — Swiss and Liechtenstein portfolio bonds and private placement structures sold as tax-efficient, which require careful analysis under both UK chargeable event rules and US rules on foreign insurance products, and which rarely deliver the treatment the sales literature implied. Add the Model 2 reporting architecture and the enforcement history attaching to Swiss banking, and these are the files where getting the sequencing right matters most.

Singapore, Hong Kong and the UAE

All three exchange information with the UK. Singapore adds a wrinkle in the form of Central Provident Fund balances, whose UK and US treatment is contested and requires a defensible position rather than silence. UAE accounts attract attention because the absence of local income tax means there is no foreign tax credit to soften either the UK or the US liability — the disclosed income is taxed twice over in the sense that both authorities want their full share and neither has anything to relieve. Hong Kong brokerage accounts frequently hold non-reporting funds, producing the same PFIC and offshore income gain overlap as their Channel Islands equivalents.

How far back does each authority reach?

The two look-back periods are not aligned, and clients are consistently surprised by the gap. The US streamlined submission is bounded: three years of returns and six years of FBARs. The UK reach is behaviour-dependent and considerably longer for offshore matters, with an extended assessment window applying to offshore income and gains and the longest period reserved for deliberate behaviour.

The practical consequence is that a client can complete a full US streamlined filing and still owe HMRC for years that fall entirely outside the US submission. Budgeting for the disclosure on the basis of the US look-back alone produces a serious underestimate. Our private client team models both exposures before any submission is made, so the total cost is known at the outset rather than discovered halfway through.

What does a properly built coordinated disclosure look like?

• Complete the account inventory first. Every account in every jurisdiction, including closed ones, joint accounts, accounts over which the client merely holds signature authority, and accounts held through structures. Statements are reconstructed from the institutions where records are missing — a process that can take months in Switzerland and should be started immediately.
• Determine residence and status year by year. UK residence under the statutory residence test, and US status and non-residency-test qualification, for every year in scope. This is what determines which routes are available.
• Classify the behaviour once. A single documented assessment supporting both the US non-willfulness certification and the UK behaviour classification, or an early recognition that the streamlined route is not available.
• Compute both liabilities from one dataset. Sterling and dollar computations from the same source figures, with PFIC, offshore income gain, chargeable event and pension analyses carried out once and applied to both.
• Model the foreign tax credit position. Including basket allocation and the timing effects that determine filing order.
• Notify HMRC and obtain the Disclosure Reference Number at the point the timeline supports completing within the 90-day window.
• Prepare Form 14653 and the UK disclosure report as companion documents, reviewed side by side for factual consistency before either is released.
• File, pay, and document the whole process so that any subsequent enquiry from either authority can be answered from a single organised file.

If you want to understand the scale of the FBAR component before committing to a course of action, our FBAR penalty calculator gives an indication of the exposure that a properly executed streamlined submission is designed to remove. For the UK side, our UK tax specialists handle the WDF process end to end.

The mistakes that cost the most

• Filing one side only. A clean US streamlined submission with an outstanding UK offshore position is not resolution; it is half a solution with an enforcement clock still running.
• Using two unconnected advisers. The contradictions this produces are exactly the contradictions both authorities are equipped to detect.
• Quiet disclosure. Filing amended returns without the formal certification, or amending a Self Assessment return without the WDF, forfeits the protection of the programmes and is treated unsympathetically on both sides.
• Waiting. Every month of delay erodes the unprompted position, and the arrival of a nudge letter or FATCA letter is not a warning shot — it is confirmation that the data has already been matched.
• Treating structures as out of scope. Trusts, foundations, personal investment companies and insurance wrappers in these jurisdictions carry their own reporting obligations, and omitting them leaves the disclosure incomplete in the one way that matters.

Speak to us in confidence

If you are a US citizen or green card holder resident in the UK with unreported balances in Jersey, Guernsey, the Isle of Man, Switzerland, Singapore, Hong Kong or the UAE, the position is resolvable — but it is resolvable properly only once, and only if both submissions are built from the same set of facts by people who understand both systems. We handle the full scope: the streamlined filing, the WDF disclosure, the PFIC and trust analysis, the foreign tax credit modelling, and the correspondence with both authorities. Every conversation is confidential and without obligation. Contact our cross-border team to arrange a private consultation, or read more about how we support US-UK dual filers through disclosure and beyond.