Offshore Disclosure and Schedule 24 Inaccuracy Penalties
Offshore disclosure and Schedule 24: how HMRC grades behaviour, why territory category multiplies the penalty, and what unprompted timing saves. Talk to us.
How behaviour sets the penalty range
An Offshore disclosure under Schedule 24 Finance Act 2007 is priced on three variables: your behaviour, the territory category of the assets involved, and whether you came forward before HMRC did. Careless behaviour in a category 1 territory can settle at nil; deliberate and concealed behaviour in a category 3 territory can reach 200% of the tax.
What Schedule 24 actually charges you on
The single most misunderstood point in an offshore catch-up is the penalty base. Schedule 24 does not charge a percentage of the offshore account balance, the portfolio value, or the income you failed to report. It charges a percentage of the potential lost revenue (PLR) — the additional UK tax properly due for the year once the inaccuracy is corrected.
That distinction is worth a great deal of money to internationally mobile clients. A UK resident with a $4m US brokerage account who under-declared $180,000 of dividends and gains is not exposed to a penalty on $4m, nor on $180,000. The penalty runs on the incremental UK tax after available double tax relief. Where US tax has already been suffered at source, or where UK/US treaty relief and foreign tax credit relief reduce the UK charge to a fraction of the headline rate, the PLR — and therefore the penalty — falls in lockstep.
This is why the first task in any offshore catch-up is not the penalty argument at all. It is the computation. Every pound of correctly claimed relief is a pound removed from the base to which a 45%, 105% or 200% multiplier might later be applied. Teams who negotiate behaviour before they have finished the arithmetic routinely leave money on the table. At Jungle Tax we finalise the PLR schedule first, then argue behaviour against a number we are confident in.
How does HMRC grade behaviour under Schedule 24?
Schedule 24 recognises four states. Only three of them carry a penalty.
Reasonable care — no penalty
If the return was inaccurate but you took reasonable care, no Schedule 24 penalty arises at all, even though the tax and interest remain payable. Reasonable care is judged against the person's own abilities and circumstances, which for a sophisticated taxpayer with global assets is a demanding standard: HMRC expects a higher level of diligence from someone with an international portfolio, a family trust or a US filing obligation than from a salaried employee with one bank account. Reliance on an adviser does not automatically establish reasonable care — you must show you took reasonable steps to give that adviser complete information and to check the output.
Careless — failure to take reasonable care
Careless is the default landing place for most genuine offshore catch-ups: an ISA-equivalent account never mentioned to the UK accountant, an overseas pension whose growth was assumed to be tax-free, a foreign rental property routed through an offshore agent, a legacy portfolio inherited and forgotten. Careless behaviour attracts the lowest penalty band and, critically, is the only band where an unprompted disclosure can be reduced all the way to nil.
Deliberate but not concealed
Deliberate means you knew the return was wrong when you signed it. It does not require an elaborate structure — a client who was told by an adviser that the foreign account was reportable, and filed anyway without it, is in deliberate territory. The consequences step up sharply: minimum penalties, exposure to the 20-year assessment window, potential naming as a deliberate defaulter, and eligibility for the asset-based penalty.
Deliberate and concealed
Deliberate behaviour accompanied by steps to hide it — nominee ownership, backdated paperwork, moving funds to frustrate exchange of information, misleading correspondence with HMRC. This is the top band and, in serious cases, the civil track runs alongside a criminal risk assessment.
Behaviour is decided inaccuracy by inaccuracy and year by year. A single disclosure covering eight years can legitimately contain careless years and one deliberate year, and the correct answer is often to segment them rather than accept a global characterisation.
Why does the territory category multiply the penalty range?
Since 2011, Schedule 24 penalties for offshore matters have been graded by where the income, gains or assets sit. HMRC groups territories into three categories according to the quality of the information-exchange relationship the UK has with them. The logic is blunt: the harder it would have been for HMRC to find the money unaided, the larger the penalty.
The multiplier only bites where the tax at stake is income tax, capital gains tax or inheritance tax. Any other tax — corporation tax, VAT, stamp duty land tax — sits in category 1 regardless of where the asset is located.
| Category | What it covers | Multiplier on the standard range |
|---|---|---|
| Category 1 | Domestic matters, plus offshore matters in listed category 1 territories (those with the strongest automatic exchange relationship with the UK). Also any tax other than IT, CGT or IHT. | Standard (1x) |
| Category 2 | The default. Any territory not specifically listed as category 1 or category 3. Crown Dependencies and UK Overseas Territories fall here unless they are individually listed elsewhere. | 1.5x |
| Category 3 | Listed territories with the weakest exchange-of-information standing. | 2x |
Two practical points matter far more than the theory. First, the categorisation is legislative and list-based, not intuitive: several jurisdictions that clients think of as "offshore" are in fact category 1 because they signed up early to automatic exchange, while some large, respectable economies are not. Never assume — check the current designation order before you concede a category. HMRC publishes the operative lists in its Compliance Handbook at CH116400.
Second, there is a separate and more aggressive rule for offshore transfers. Where income or proceeds are moved out of the territory in which they arose — and the transfer makes the inaccuracy significantly harder to detect — the applicable category is the highest category of any territory involved. A perfectly ordinary category 1 source can therefore be re-priced at category 3 by a single routing decision made years earlier for entirely commercial reasons.
The Schedule 24 offshore penalty ranges in full
For inaccuracies in returns for 2016-17 onwards, the ranges below apply. Minimums for deliberate behaviours were lifted by 10 percentage points from that year, so the year in question changes the answer — a point that matters in a catch-up spanning a decade. HMRC's operative table sits at CH116600.
| Category | Behaviour | Unprompted minimum | Prompted minimum | Maximum |
|---|---|---|---|---|
| 1 | Careless | 0% | 15% | 30% |
| 1 | Deliberate | 30% | 45% | 70% |
| 1 | Deliberate and concealed | 40% | 60% | 100% |
| 2 | Careless | 0% | 22.5% | 45% |
| 2 | Deliberate | 40% | 62.5% | 105% |
| 2 | Deliberate and concealed | 55% | 85% | 150% |
| 3 | Careless | 0% | 30% | 60% |
| 3 | Deliberate | 50% | 80% | 140% |
| 3 | Deliberate and concealed | 70% | 110% | 200% |
Read the table as a set of doors, not a sliding scale. Behaviour selects the row. Territory selects the block. Prompted versus unprompted selects which end of the corridor you start from. Only then does the quality of your disclosure move you within that corridor.
What is unprompted disclosure actually worth?
A disclosure is unprompted if it is made at a time when the taxpayer had no reason to believe HMRC had discovered, or was about to discover, the inaccuracy. Everything else is prompted — and the definition is objective, so a client's private conviction that HMRC "would never have found it" is irrelevant if a nudge letter had already landed.
The value is not marginal. Take a category 2 territory, careless behaviour, PLR of £400,000 across the disclosure period:
- Unprompted, full and early: the range runs 0% to 45%. A complete, well-evidenced disclosure can settle at or very near nil — a penalty saving of up to £180,000.
- Prompted: the floor is 22.5%. Even a flawless disclosure cannot go below £90,000. HMRC has no discretion to breach the statutory minimum other than by special reduction.
On the same facts with deliberate behaviour, the gap between an unprompted floor of 40% and a prompted floor of 62.5% is £90,000 — and that is before the asset-based penalty and publication consequences that attach only to deliberate cases. In practice, the difference between making the call this month and waiting until a letter arrives is frequently a six-figure sum.
Does a CRS or FATCA nudge letter destroy unprompted status?
In HMRC's view, generally yes. Once you have received a letter referring to information received about overseas accounts, you have reason to believe HMRC is about to discover the inaccuracy, and any subsequent disclosure is prompted. This is the operational reason offshore catch-ups are so time-sensitive: the data has already been exchanged under the Common Reporting Standard and, for US-connected clients, under FATCA. The window between the data arriving in HMRC's systems and the letter arriving in your postbox is the entire value of unprompted status.
Two related cautions. A "certificate of tax position" enclosed with a nudge letter is not a statutory form and there is no legal obligation to sign it; signing one carelessly can create a fresh, separately penalisable false statement. And a nudge letter about one account does not necessarily make a disclosure about a wholly unrelated, unmentioned matter prompted — that argument is available, but it must be run deliberately and documented at the time.
How the quality of disclosure moves you within the range
Within the corridor set by behaviour, territory and prompting, HMRC reduces the penalty for the quality of disclosure. The reduction is conventionally split three ways — telling, helping and giving access — and weighted, with helping carrying the largest share. HMRC's framework is set out at CH82470.
- Telling — admitting the inaccuracy, explaining how and why it arose, and disclosing the full extent without being asked account by account. Volunteering the years HMRC has not asked about is what earns full marks here.
- Helping — the largest component. Producing the computations, quantifying the PLR yourself, reconciling foreign currency, identifying and applying treaty relief, and answering questions quickly and completely. A disclosure that arrives as a finished, agreed-format computation rather than a bundle of statements is worth real money.
- Giving access — providing bank records, custodian statements, trust accounts and correspondence promptly, including documents HMRC could not compel from an overseas institution.
The word HMRC uses is quality, and quality includes timing, nature and extent. A disclosure made three years after the client first suspected a problem is a lower-quality disclosure than the same disclosure made three months after, even where the content is identical. Delay is scored against you explicitly.
The US×UK interaction most guides miss
For our client base — US persons resident in the UK, UK residents with US assets, dual filers, and accidental Americans — four cross-border effects change the analysis materially.
1. The United States is a category 1 territory
US-source income, US brokerage accounts and US real estate generally sit in category 1, meaning the offshore multiplier does not apply and the range is the standard 0-30% careless band. This is counter-intuitive to clients who assume anything "foreign" is penalised harder. The practical consequence: a UK resident catching up on unreported US dividends, IRA distributions or 401(k) growth is usually in a far better penalty position than one catching up on a portfolio held in an unlisted jurisdiction. Note the carve-out, though — US overseas territories and possessions are treated separately from the United States itself.
2. Treaty relief and foreign tax credits shrink the base before the multiplier applies
Because the penalty is a percentage of PLR, correctly claimed US foreign tax credits, treaty-based positions on pensions and government service income, and relief for US tax on gains all reduce the penalty as well as the tax. Time-limit rules for claiming credit relief run separately from the disclosure, so late claims must be made properly and promptly. This is technical work that generalist disclosure practices routinely under-perform, and it is the highest-return hour of the whole engagement. See our approach to cross-border tax matters and dual US-UK filing.
3. Sequencing a UK disclosure alongside an IRS catch-up
Many clients need both: a UK Schedule 24 disclosure and a US catch-up through the Streamlined Foreign Offshore Procedures, delinquent FBAR submission or delinquent international information return procedures. The two regimes are independent but not isolated. The US Streamlined route requires a non-wilfulness certification; the UK route requires a behaviour characterisation. It is materially unhelpful to certify non-wilful conduct to the IRS while conceding deliberate behaviour to HMRC on the same facts, or vice versa. The narrative of why the accounts went unreported must be written once, be true, and hold in both jurisdictions. Getting that wrong closes the door on the IRS Streamlined Filing Compliance Procedures, which the IRS describes in detail on irs.gov.
4. UK-resident US persons and the "offshore" label
For a US person living in London, their UK accounts are domestic to HMRC and foreign to the IRS. The same portfolio is simultaneously a category 1 domestic matter for Schedule 24 purposes and a reportable foreign financial account for FBAR and Form 8938. A catch-up therefore often produces a modest UK penalty exposure alongside a substantial US information-return exposure, or the exact reverse. Sizing the two independently, before either is filed, is what allows sequencing decisions to be made rationally.
| Feature | UK — Schedule 24 FA 2007 | US — IRS civil penalties |
|---|---|---|
| Penalty base | Potential lost revenue (extra UK tax) | Underpayment of tax; FBAR penalties run on account balances, not tax |
| Standard rate for non-deliberate error | 0-30% (category 1), up to 0-60% (category 3) | 20% accuracy-related penalty on the underpayment |
| Deliberate / fraudulent conduct | Up to 100%, 150% or 200% by territory category | 75% civil fraud penalty; wilful FBAR penalties by reference to account value |
| Voluntary catch-up route | Digital disclosure service / offshore disclosure; unprompted status prized | Streamlined Foreign or Domestic Offshore Procedures; Voluntary Disclosure Practice |
| Reward for coming forward first | Careless unprompted can reach 0% | Streamlined Foreign Offshore: no penalty; Domestic: 5% Title 26 miscellaneous offshore penalty |
| Assessment window | 4 / 6 / 12 years offshore; 20 years deliberate | 3 years, 6 years for substantial omissions, unlimited where no return or fraud |
| Information return failures | Penalty attaches to the tax, not the form | Standalone penalties per unfiled 8938, 5471, 3520 and FBAR |
The tail risks that sit on top of Schedule 24
Failure to Correct
Offshore non-compliance relating to tax years up to and including 2015-16 that still existed on 6 April 2017 and was not corrected by 30 September 2018 falls into the Failure to Correct regime rather than the ordinary Schedule 24 ranges. FTC penalties start at 200% of the tax and, on a full and accurate disclosure, are reduced only to a floor of 100% unprompted or 150% prompted — multiples of what the equivalent Schedule 24 penalty would have been. Reasonable excuse is available but narrow, and specifically excludes reliance on advice that was not impartial. Any catch-up reaching back before 2016-17 must be screened for FTC exposure at the outset, because it changes the negotiation entirely.
Asset-based penalties
Where a deliberate offshore inaccuracy involves capital gains tax, inheritance tax or asset-based income tax and the offshore PLR for a tax year exceeds a statutory threshold, HMRC can charge an additional penalty calculated by reference to the value of the asset itself, subject to a cap. This is the one place where the offshore regime does bite on capital rather than tax, and it is deliberate-only — another reason the careless/deliberate line is worth fighting for on the evidence.
Publication of deliberate defaulters
HMRC may publish the names and details of taxpayers penalised for deliberate defaults above a statutory tax threshold. Publication is disapplied where the penalty has been reduced to the statutory minimum for an unprompted disclosure with full co-operation. For a founder, executive or public-facing individual, that reputational carve-out is frequently the decisive argument for moving now rather than waiting.
Extended assessment windows
The ordinary four-year and careless six-year windows are extended to 12 years for offshore matters in income tax, capital gains tax and inheritance tax, with the 20-year window retained for deliberate behaviour. A catch-up therefore routinely spans more years than clients expect, and the further back it reaches, the more the year-by-year differences in penalty minimums matter.
Special reduction, suspension and appeals
HMRC may apply a special reduction below the statutory minimum in exceptional circumstances. It is genuinely exceptional — inability to pay is expressly not a special circumstance — but it exists and should be raised where the facts support it, for instance where an inaccuracy arose from serious illness or from a systemic failure by a third party the taxpayer could not have detected.
A careless penalty may be suspended for up to two years against conditions designed to prevent recurrence. Suspension is unavailable for deliberate penalties, and in practice difficult where the client will have no further returns of that type — a departing non-resident, for instance. Where the client will continue filing UK returns with the same offshore assets, suspension is worth requesting explicitly rather than hoping it is offered.
Penalty decisions carry appeal rights to HMRC review and the First-tier Tribunal. Behaviour findings and territory categorisation are both appealable; the quantum of a reduction for quality of disclosure can be challenged as unreasonable. Appeal deadlines are short and run from the penalty assessment, not from the settlement discussions.
What is changing: the behavioural penalties reform
HMRC consulted in 2025 on reforming behavioural penalties, canvassing both a targeted simplification of the existing Schedule 24 architecture and a more radical model that would merge inaccuracy and failure-to-notify penalties into a single misdeclaration penalty, with a separate and more punitive civil evasion penalty for serious deliberate non-compliance. Nothing in the current ranges has yet changed, and any reform would take time to legislate and commence. The planning point is simple: penalty regimes in this area have moved in one direction for fifteen years, and a disclosure made under today's rules is priced under today's rules. Waiting for a friendlier regime has never yet been the winning strategy.
A practical sequence for an offshore catch-up
- Fact-find under privilege where available, and before anything is filed. Identify every account, structure, pension, life policy and property, and the territory each sits in.
- Screen for Failure to Correct and for deliberate-only consequences — asset-based penalty and publication — because these determine the shape of the whole engagement.
- Build the PLR schedule properly, with full treaty relief and foreign tax credit claims, before discussing behaviour with anyone.
- Fix the behaviour narrative once, in writing, and make sure it is consistent with anything being said to the IRS.
- Register and disclose promptly to protect unprompted status and to score well on timing.
- Present the disclosure as finished work — computations, reconciliations, source documents — to maximise the telling, helping and giving access reductions.
- Sequence the US filings so that certifications and characterisations align across both jurisdictions.
Further reading on the offshore categorisation framework sits in HMRC's Compliance Handbook offshore inaccuracies guidance, and our wider library is at our full guides library. For clients whose exposure spans both systems, our private client team handles the UK and US sides in one engagement rather than two.
Speak to us before the letter arrives
The difference between an unprompted and a prompted offshore disclosure is measured in tens or hundreds of thousands of pounds, and the window closes the day HMRC writes to you. If you have unreported overseas income, an undeclared account, a foreign pension or a structure you are no longer confident about, the right time to have this conversation is now. Contact our cross-border team for a confidential, privileged discussion of your position — no obligation, no judgement, and a clear view of your exposure and your options in both jurisdictions before anything is filed.
