Introduction: Why Section 1256 Catches London Traders Off Guard
Section 1256 forces you to pay American tax on futures positions you have not sold, on a date Britain does not recognise, at a blended rate no British form understands. That is three mismatches in one sentence, and every one of them costs money. Section 1256 creates all three. Furthermore, none of them appear on the trading platform statement you hand your accountant each January.
American investors in London meet this rule constantly. Specifically, anyone holding index futures, commodity contracts or non-equity options at the close of business on 31 December falls inside it. Consequently the position is treated as sold, taxed, and repurchased, even though the contract sits open in your account on New Year's Day.
Meanwhile Britain does nothing at all until you actually close out. Therefore the two countries tax the same profit in different years, which is precisely the situation the foreign tax credit handles badly. Additionally, a quirk in the American sourcing rules can strip the credit away completely.
At TaxYork we prepare returns on both sides for traders, fund principals and private investors. Notably, almost every published guide to this topic assumes the reader lives in Chicago. This one assumes you live in Clerkenwell.
How Section 1256 Actually Works
What Section 1256 Treatment Means for Your Return
Section 1256 replaces ordinary capital gains timing with a compulsory annual settlement. Each qualifying contract held at year end is treated as sold for its fair market value on the last business day of the tax year, and reopened at that price. Consequently unrealised profit becomes taxable profit, and unrealised losses become deductible losses.
The rule then splits the result on a fixed ratio. Sixty per cent counts as long-term capital gain or loss and forty per cent counts as short-term, irrespective of how long you actually held the position. Therefore a contract opened in December and marked at the end of the same month still receives sixty per cent long-term treatment. The statutory language sits in section 1256 of the Internal Revenue Code.
Furthermore, the blend produces a genuinely favourable American rate. At the top bracket the mix of 20 per cent and 37 per cent lands near 26.8 per cent before the investment surcharge. Additionally, that beats the 37 per cent an equivalent short-term equity trade would suffer.
Which Instruments Fall Inside Section 1256
Section 1256 applies to five categories: regulated futures contracts, foreign currency contracts, non-equity options, dealer equity options and dealer securities futures contracts. Consequently index options, commodity futures and most exchange-traded futures qualify, while ordinary single-stock options do not.
The exclusions matter as much as the inclusions. Specifically, a securities futures contract held by anyone other than a dealer sits outside the rule, and so do most notional principal contracts and swaps. Therefore your single-name equity options remain outside Section 1256 and stay on the normal realisation basis, reported through Schedule D in the ordinary way.
Additionally, a British spread bet is not a contract of this kind at all, because it is a wager rather than a regulated futures position. We covered that separately in our guide to spread betting and US tax for Americans in Britain. Nevertheless the American treatment of a spread bet is far harsher than the treatment described here.
Reporting Through Form 6781
Every mark-to-market result runs through Form 6781, headed Gains and Losses From Section 1256 Contracts and Straddles. Part I aggregates realised and unrealised amounts into a single net figure. Consequently the form then allocates forty per cent to short-term and sixty per cent to long-term, and both figures carry to Schedule D.
Furthermore, the aggregation is genuinely net. Losses on closed positions offset marked gains on open ones within the same computation. Therefore a trader who closed badly in November but holds a strong open book on 31 December reports only the combined outcome.
Additionally, Publication 550 sets out the interaction with the straddle rules in section 1092. Notably, offsetting positions can defer losses you expected to claim, which surprises investors running hedged books.
The Qualified Board or Exchange Problem Nobody Explains
Why the Exchange Decides Whether Section 1256 Applies
A regulated futures contract only earns Section 1256 treatment if it trades on a qualified board or exchange. Subsection (g)(7) defines that term as a securities exchange registered with the Securities and Exchange Commission, a domestic board of trade designated by the Commodity Futures Trading Commission, or any other market the Secretary of the Treasury determines has adequate rules.
Consequently the venue, not the instrument, controls whether Section 1256 applies at all. Therefore two economically identical contracts can receive different American treatment purely because one traded in Chicago and the other did not. Additionally, this is the single most common error we see in London portfolios.
Nevertheless the position is knowable. Specifically, Treasury has issued a series of revenue rulings designating individual foreign exchanges, and each ruling carries its own effective date.
The Foreign Exchanges Treasury Has Designated
ICE Futures Europe received designation through Revenue Ruling 2007-26. Furthermore, the London International Financial Futures and Options Exchange was designated by Revenue Ruling 2010-3, effective for contracts entered into on or after 1 January 2010. Eurex Deutschland followed under Revenue Ruling 2013-5.
Additionally, the list has continued to grow. ICE Futures Canada was designated under Revenue Ruling 2009-24 and the Dubai Mercantile Exchange under Revenue Ruling 2009-4. More recently Revenue Rulings 2024-22 and 2024-23 brought in the Bourse de Montréal and the European Energy Exchange.
Therefore a London investor trading ICE Futures Europe or the former LIFFE contracts genuinely does receive Section 1256 treatment. However, an investor using a venue absent from the list does not, and the difference is roughly ten percentage points of tax.
What Happens When the Exchange Does Not Qualify
Where the venue lacks designation, the contract falls back to ordinary capital gains rules. Consequently Section 1256 never engages, so there is no year-end mark, no sixty-forty blend, and the full gain is short-term if you held for a year or less. Therefore the top American rate becomes 37 per cent rather than roughly 26.8 per cent.
Furthermore, the fallback is not always worse. A trader sitting on large unrealised gains at year end may prefer deferral to the compulsory mark. Accordingly the venue choice deserves a deliberate decision rather than an accident of platform default.
Additionally, remember that the designations change. Notably, Treasury adds exchanges as it reviews their rules, so a venue that failed the test three years ago may qualify now. We check the current position each filing season rather than relying on a stale list.
Where Section 1256 Collides With the British System
Britain Taxes Realisation, Not the Year End
The United Kingdom charges capital gains tax on futures under section 143 of the Taxation of Chargeable Gains Act 1992, and on traded options under sections 144 and 144A. Crucially, the charge arises when you close out, deliver or let the contract lapse. Consequently Britain recognises nothing whatsoever on 31 December.
HMRC sets the treatment out in its capital gains manual, where CG56004 confirms the capital treatment and CG56081 deals with contracts not closed out. Furthermore, CG55536 summarises traded options, and the underlying wording appears at section 143 TCGA 1992 and section 144.
Additionally, HMRC accepts that individuals rarely carry on a trade of dealing in futures. Therefore the charge is almost always capital gains tax rather than income tax, which is the better outcome for a Section 1256 investor seeking to match credits.
The Timing Mismatch That Strands Your Credit
Here lies the real damage. American tax falls in the calendar year of the mark, whereas British tax falls in the tax year of the actual close-out. Consequently you can pay Washington in year one and London in year two on precisely the same profit.
The foreign tax credit cannot bridge that gap cleanly, because section 904 measures the credit against foreign source income in the year the foreign tax accrues. Therefore the Section 1256 tax arrives with no British tax to credit, and the British tax arrives with no American liability left to relieve. Additionally, the credit that does arise lands in the passive basket, where it competes with dividends and interest.
Furthermore, the two year ends are themselves misaligned. The American year closes on 31 December and the British year closes on 5 April. Consequently even a position closed in February straddles the boundary, and the foreign tax credit rules must be applied across two overlapping periods.
The Section 865 Trap That Can Kill the Credit Outright
Capital gains on personal property are sourced by reference to the residence of the seller under section 865. Consequently an American whose tax home sits in London generally produces foreign source gains, which is exactly what a foreign tax credit needs.
However, subsection (g)(2) contains a trap. Where the gain is not subject to foreign tax of at least ten per cent, the citizen is treated as an American resident instead. Therefore the gain becomes American source, and the credit disappears entirely.
This bites more often than you would expect. Specifically, the £3,000 annual exempt amount, brought-forward British losses, or a year with modest gains can all pull the effective British rate under ten per cent. Additionally, the calculation is made gain by gain rather than across the portfolio, so a single sheltered disposal can fall out of the credit even when the rest qualifies.
The Rate Arithmetic in Both Countries
What Britain Charges in 2026 and 2027
British capital gains tax runs at 18 per cent within the basic rate band and 24 per cent above it, with an annual exempt amount of £3,000 for the 2026 to 2027 year. The government guidance on rates and allowances confirms both figures.
Consequently a higher or additional rate taxpayer in London pays 24 per cent on futures gains. Furthermore, that sits below the American short-term rate but above the blended Section 1256 rate of roughly 26.8 per cent only in the sense that the two are close enough for basket mechanics to decide the outcome.
Additionally, the surcharge changes the comparison. The 3.8 per cent charge under section 1411 applies to these gains once modified adjusted gross income exceeds $200,000 single or $250,000 married filing jointly. Therefore the true American cost approaches 30.6 per cent, and no credit relieves the surcharge portion.
Loss Relief Runs in Opposite Directions
American law offers something genuinely generous here. Under section 1212(c) a net Section 1256 contracts loss can be carried back three years, by ticking box D on Form 6781. Consequently a bad year can reclaim tax paid on marked gains in earlier years.
Nevertheless the carryback is narrow. Specifically, it offsets only net section 1256 contract gain in the earlier year, it cannot create or increase a net operating loss, and the recovered amount keeps the forty-sixty character. Therefore it rescues a futures trader and nobody else.
Britain runs the opposite way. Capital losses carry forward indefinitely once claimed, yet they cannot be carried back at all, as the government guidance on capital losses explains. Consequently a loss year can generate an American refund and a British carryforward simultaneously, which quietly destroys the credit position in both directions.
Currency Contracts and the Section 988 Overlay
Foreign currency contracts sit inside Section 1256 by default, yet they also fall within the ordinary income rules of section 988. Consequently the interaction requires a decision rather than a default.
Furthermore, an investor can elect out of capital treatment for certain forward contracts, or elect capital treatment where the regulations permit, under the mechanics at 26 CFR 1.988-3. Therefore the election should be made deliberately and documented contemporaneously, because it cannot be reconstructed later.
Additionally, sterling exposure complicates every figure on the return. Notably, an American reports in dollars while the British computation runs in pounds, so a flat position in one currency can show a gain in the other.
A Worked Case Study: A London Macro Trader
The Positions and the Year End
Consider Elena, an American citizen and a portfolio manager living in Islington. She trades ICE Futures Europe contracts through a London broker in her personal account. During 2026 she realises $180,000 of closed gains and holds an open book showing $120,000 of unrealised profit at the close on 31 December.
Because ICE Futures Europe is a designated qualified board or exchange, Section 1256 applies to the whole book. Consequently her Form 6781 reports $300,000, not the $180,000 her platform statement describes as realised. Furthermore, the split gives $180,000 long-term and $120,000 short-term.
Elena assumed the open positions were simply open. Instead, the American system had already settled them.
The American Bill
At the top bracket the blended charge on $300,000 lands near $80,400. Additionally, the surcharge under section 1411 adds a further $11,400, because her income comfortably exceeds the joint threshold. Therefore her total American cost for 2026 is roughly $91,800.
Crucially, Britain charged nothing in that period on the open $120,000. Consequently Elena had no British tax to credit against the marked portion, and her Form 1116 relieved only the realised element.
Furthermore, the $120,000 was taxed at American rates with essentially no relief. Notably, this is not double taxation in the technical sense, yet it produces the same feeling and the same cash outflow.
The British Bill a Year Later
Elena closed the remaining book in March 2027 at a slightly better level, realising $128,000 against the marked base. Britain then charged capital gains tax on the whole economic gain measured from her original purchase price, because the American mark has no British significance whatsoever.
Consequently the British charge fell on roughly £97,000 at 24 per cent, or about £23,300. Additionally, that tax arose in the 2026 to 2027 British year and reached her American 2027 return, where the corresponding income had already been taxed in 2026.
Therefore the credit had nowhere useful to go. Specifically, her 2027 passive basket contained little American liability, and the excess simply joined a carryforward she is unlikely to use.
What We Changed for 2027
We restructured the year end rather than the trading. Specifically, Elena now reviews her open book in the second week of December and closes or reduces positions where the American mark would create tax with no matching British charge. Consequently the two systems settle in the same period far more often.
Furthermore, we filed a section 1212(c) carryback claim when her 2027 book turned negative, recovering part of the 2026 tax. Additionally, we documented her exchange venues so that every contract's qualified board status is evidenced rather than assumed.
Above all, we moved her from a platform report to a genuine computation. In our experience that single change is worth more than any election.
Missed Reporting and How to Correct It
The Returns That Never Showed the Mark
A large share of the cases we see involve open positions that were simply never marked. Consequently the return shows only the realised trades from the broker summary, and the Section 1256 computation never happened.
Furthermore, British brokers rarely produce anything resembling Form 6781. Therefore the preparer receives a contract note history and no year-end valuation, and the omission is invisible on the face of the return.
Additionally, the omission is usually genuinely non-wilful. Notably, it arises from a reporting gap rather than a decision, which matters a great deal when choosing a correction route.
Bringing the Filings Back Into Line
Where the taxpayer qualifies, the Streamlined Filing Compliance Procedures allow three years of amended or delinquent returns and six years of foreign bank account reports, with the offshore penalty waived for those meeting the foreign residence test. Consequently long-term London residents usually have a clean route back.
Nevertheless the arithmetic frequently favours the taxpayer. Specifically, marking an open book in a losing year creates deductible losses that were never claimed, so a properly rebuilt computation can produce a refund rather than a liability. Our IRS Streamlined Filing specialists assess the direction of travel before anything is filed.
Additionally, the accounts holding the margin need their own review. Furthermore, a London brokerage account is a foreign financial account for reporting purposes and frequently a specified foreign financial asset as well, which our FBAR and FATCA reporting team handles alongside the income work.
How TaxYork Can Help
Building the Computation Both Countries Need
We prepare the American mark-to-market schedule and the British capital gains computation from one working file. Consequently the two sets of figures reconcile, and the credit claim rests on evidence rather than estimate. Furthermore, we value every open position at the correct year-end date and record the exchange venue for each contract.
Additionally, we model the December position before the year closes. Therefore clients can decide whether to carry an open book into the mark or settle it, with the tax consequence quantified rather than guessed.
Rescuing the Credit Position
Many new clients arrive with several years of stranded credits and no schedule explaining them. Consequently we rebuild the basket history, test the section 865 sourcing on each Section 1256 gain, and identify where the ten per cent threshold failed.
Moreover, we file carryback claims where a loss year permits one. Our treaty and foreign tax credit team handles the relief side, while our cross-border planning specialists restructure the position for future years. You can review our full range of services at any time.
Conclusion
Section 1256 hands American investors a genuinely attractive blended rate and then attaches a settlement date that Britain refuses to recognise. Consequently the benefit and the burden arrive in different years, and the foreign tax credit struggles to connect them. Furthermore, the section 865 sourcing rule can remove the credit altogether when the British charge falls below ten per cent of the gain.
Nevertheless the position is manageable with preparation rather than reaction. Specifically, confirm that each venue is a designated qualified board or exchange, value the open book before December closes, and decide deliberately whether to carry positions across the mark.
Above all, treat the year end as a tax event rather than a calendar event. In summary, a Section 1256 book that is reviewed in December costs materially less than the same book reviewed in April.
Contact Us
If you trade futures or non-equity options from Britain and hold positions across the year end, we can build the computation properly and test whether your credits actually work. Furthermore, we can review earlier years for unclaimed losses and missed marks.
Call us on 020 3488 8606 or email hello@taxyork.com. Alternatively, book a consultation and we will review your position within one working week.
Disclaimer
This article provides general information on United States and United Kingdom tax matters and does not constitute tax or legal advice for any particular person or transaction. Tax law changes frequently, and the treatment of any individual depends entirely on their specific facts and circumstances. Furthermore, the list of designated qualified boards and exchanges is revised from time to time and should be confirmed before filing. Accordingly you should obtain professional advice tailored to your situation before acting on anything set out here. TaxYork accepts no liability for any loss arising from reliance on this material.