Trading US options from the UK

Options listed in the US, on US shares, ETFs and indices, are open to UK residents through FCA-authorised brokers and through US ones. Trading them from the UK brings a layer that ICE contracts do not: a US tax form, US withholding on anything that pays a dividend, US trading hours that fall in the UK evening, dollar amounts that must be converted leg by leg, and two traps that arrive only when an option is assigned: US fund units that the UK taxes as income, and US estate tax. This page covers that layer, with each rule worked in pounds. The option tax itself is on the UK tax worked examples page, and the firms on the broker feature matrix.

Used on: long call · covered call · bull call spread · long straddle · poor man's covered call · the Wheel · jade lizard · tax: two dates, two rates

The W-8BEN: one form, three jobs

Form W-8BEN is the certificate a US payer or broker needs before it treats an account holder as a non-US person. It does three separate things for a UK resident:

1. It establishes foreign status. The IRS instructions say the form is also used "to claim an exception from domestic information reporting and backup withholding" on items such as broker proceeds. Without it, a US payer can apply backup withholding, which the IRS sets at 24%, to payments such as the proceeds of a sale.
2. It claims the treaty rate on US dividends. Under the UK-US treaty, US tax on a portfolio dividend paid to a UK resident is capped at 15%; without the claim the rate is 30%. Options never pay dividends, but shares delivered by an assigned put or an exercised call do.
3. It covers dividend equivalents. Payments under section 871(m) are treated as US-source dividends (IRS Publication 515), so the same dividend claim is what applies if those rules ever reach a position (see below: ordinary listed options are outside them until 2029).

The form lasts, in the IRS's words, from signing "until the last day of the third succeeding calendar year": a form signed on Monday 17 August 2026 stays in effect until 31 December 2029. It lapses early if the facts on it change, such as a move out of the UK, and the IRS instructions give 30 days to tell the payer.

What the US withholds, and what the UK return does with it

One quarterly dividend, four taxpayers

A written put on a US share is assigned and 100 shares arrive in the account. Suppose the next quarterly dividend is $0.50 a share (a hypothetical figure), so $50.00 gross, which is £36.88 at the model rate. The US takes $7.50 with the treaty claim (£5.53) or $15.00 without it (£11.06). What the UK then adds depends on where the dividend falls. GOV.UK's foreign income guidance says the credit is smaller when the income "would have been taxed at a lower rate in the UK", or when the treaty sets a lower rate than was withheld.

The lesson is where the 15% ends up. For a higher-rate taxpayer it is a prepayment of UK tax. Inside the allowance, or at the basic rate, it is a cost that the UK return cannot recover, and without the form the extra 15% is not creditable at all. The allowance and rates are the 2026/27 figures on GOV.UK.

Section 871(m): ordinary listed options are outside it until 2029

Section 871(m) of the US Internal Revenue Code treats "dividend equivalent" payments on certain equity derivatives held by non-US persons as US-source dividends, so withholding can reach a derivative in the way it reaches the share. The rules have applied to delta-one transactions since 2017. IRS Notice 2026-61, published in September 2026, extends the relief in Notice 2024-44 by two years: the Treasury and the IRS intend to amend the regulations so that they "will not apply to any payment made with respect to any non-delta-one transaction issued through 2028". An ordinary listed call or put is not delta-one, so contracts issued before 1 January 2029 are outside the regime, although the anti-abuse rule continues to apply.

From 2029 a contract can be tested, and a long-dated call deep in the money, whose value moves almost one for one with the share, is the kind of position the rules were written for. The notice says the IRS will take good-faith efforts into account for non-delta-one transactions in 2029. Brokers, not account holders, calculate and withhold; any withholding would appear on the year's US tax statement and would be claimed on the UK return in the same way as dividend withholding. The relief has been extended several times since 2017.

US hours and exercise cut-offs in UK time

US share options trade from 09:30 to 16:00 Eastern Time, which is 14:30 to 21:00 in the UK for most of the year; options on SPY, QQQ, IWM and a list of other broad ETF and index classes trade on until 16:15 (21:15 UK). The decisions that matter at expiry come later: FINRA Rule 2360(b)(23)(A) gives option holders "until 5:30 p.m. Eastern Time" on the expiry day to make a final exercise decision, which is 22:30 UK. Each firm then sets its own, earlier cut-off for instructions from its clients. The chart shows both, for a normal week and for a week when the clocks disagree.

The weeks when the gap is four hours

US clocks change on the second Sunday of March and the first Sunday of November; UK clocks on the last Sundays of March and October. In between, New York is four hours behind London instead of five. The mismatch weeks from the model date to the end of 2027 are 26 to 30 October 2026, 15 to 26 March 2027 and 1 to 5 November 2027. The monthly expiry on Friday 19 March 2027 falls inside one of them, and so do the weekly and daily expiries of those weeks: on those days the industry cut-off is 21:30 UK and each firm's cut-off moves an hour earlier with it.

What the UK evening changes at expiry

• After-hours moves. An option's status at expiry follows the closing price, but a holder can still instruct until the cut-off, so a share that moves after 21:00 UK can turn a short option that closed out of the money into one that is exercised against its writer. The mechanics, and why a spread is fully defined only once both legs are settled, are on the assignment page.
• Automatic exercise. Expiring equity options that finish $0.01 or more in the money are exercised unless the holder instructs otherwise, so an account that cannot pay for 100 shares per contract depends on its firm's handling. tastytrade says its risk team may close positions before the close on expiry day and blocks new sales to open in the last 30 minutes; Robinhood UK says it may sell an in-the-money contract in the last 30 minutes if the account cannot take delivery; Webull UK takes no exercise instructions on expiry day and may close a position before the close when the account lacks the buying power or shares to settle it. The broker matrix sets these side by side.
• Standard SPX stops on Thursday. The third-Friday SPX series is A.M.-settled: trading ends the business day before, and the settlement value comes from Friday's opening prices, around 14:30 UK. A UK holder cannot trade out of a standard SPX position on the settlement morning; the P.M.-settled SPXW series trade to 16:00 Eastern on their expiry day.
• Settlement. Shares delivered on exercise or assignment settle T+1 in the US. ICE UK stock options deliver two business days after exercise; UK T+1 is planned from 11 October 2027.

The assignment page's expiry-day timeline sets the US lanes beside the ICE and FTSE 100 ones for the same Friday.

SPX, XSP or SPY: one index, three settlement routes

The S&P 500 can be traded through options on the index itself (SPX), a one-tenth version of it (XSP) or options on an ETF that holds it (SPY). The price exposure is similar. What reaches the account at expiry, and so the UK tax route, is not.

In money: a 7,600 put on SPX for the standard September expiry, 32 days out, has a model value of $69.09, which fills at $69.10 on the $0.10 tick: $6,910.00 for one contract, or £5,096.25. The XSP 760 put for the same date has a model value of $6.91, or $690.94 per contract: one-tenth, as the contract sizes say. The model probability that the put finishes in the money is 32.0% (risk-neutral, lognormal, IV 15.19%). SPX and XSP settle in cash, so the tax is the s144A computation on the tax page; an assigned SPY put instead leaves the account holding fund units.

Assigned into a US ETF: the offshore fund rules

An option on SPY, QQQ or IWM is settled by delivering units in a US-domiciled fund. For UK tax, a US ETF is an offshore fund, and HMRC's helpsheet HS265 draws the line on one question: does the fund have reporting fund status? For a fund without it, "any gain you realise will normally be treated as an 'offshore income gain'", and "You will be subject to Income Tax, rather than Capital Gains Tax", reported on the foreign pages (SA106). A reporting fund's units stay within capital gains tax, although its reported income is taxed each year even when it is not paid out.

Overseas funds can be marketed to UK retail investors only if they are recognised schemes, and the FCA says "there are currently no US funds that are recognised schemes in the UK" (policy statement PS25/20), which is why UK retail accounts are generally not offered SPY to buy. Physical settlement can still deliver the units, which is how a UK account can come to hold them. How each firm then treats units delivered this way is not set out on the pages we checked.

The same $4,000 gain, taxed two ways

A written SPY put with a $760 strike is assigned, and 100 units arrive for $76,000 (£56,051.33). They are later sold at $800. The prices are illustrative, and one exchange rate, $1.3559, is used for both dates to isolate the fund rule; a real computation converts each date at its own rate (two dates, two rates). The put's premium would reduce the units' cost under s144(2)(b); it is left out here.

For a higher-rate taxpayer the fund rule costs £472.01 more on this gain than CGT at 24%, and it removes the exempt amount altogether, since an offshore income gain is income. A Wheel run on SPY meets it on every turn that ends with units called away. The income tax rates shown are the UK main rates for 2026/27 on GOV.UK; a Scottish taxpayer's rates on this income may differ. Derived: HMRC gives no worked example of an option assigned into a non-reporting fund; this combines s144(2) with HS265. Questions about a particular holding belong with a tax adviser.

US estate tax on shares that arrive by assignment

The IRS says the executor of a person who was neither a US citizen nor US resident must file an estate tax return, Form 706-NA, "if the fair market value at death of the decedent's U.S.-situated assets exceeds $60,000", and its list of US-situated assets includes "Stock of corporations organized in or under U.S. law". That is £44,251.05 at the model rate.

An option position rarely comes near that. Assignment can: one assigned put on a share priced at $600 delivers $60,000 of US stock, and on a $100 share 6 contracts do the same. The UK and the US have an estate and gift tax treaty (the 1979 order, SI 1979/1454), and the IRS notes that such treaties often limit which assets count as situated in the US. Whether it removes a US charge for a particular estate depends on the person's domicile and circumstances, which is a question for a tax adviser, not something a page can settle.

Dollars in, pounds out: one put converted leg by leg

HMRC's manual (CG78310) converts each cost and each proceed at the rate for its own date, and rejects converting a net dollar result. For a written option closed by buying it back, s148 makes the buy-back a cost of the original grant, so both legs belong to the grant's tax year, each at its own rate. The tax page's Example 15 works a loss this way; this example shows what a currency move does to a gain.

Model inputs: a hypothetical US share (not a real company) at $100 on Monday 17 August 2026; a 95 put for Friday 16 October, 60 days, IV 30%, rate 3.625%, no dividend, American on the binomial tree: model value $2.46, filled at $2.45. On Friday 18 September the share is at $101 with 28 days left: model value $1.03, bought back at $1.05 ($105.00 a contract). Commission $1.00 an order. Rates: $1.3559 per £1 on 17 August and $1.3344 on 18 September (ECB reference-rate crosses); $1.25 is an illustrative stress rate, not a forecast.

The dollar result is identical in both columns. In sterling, a pound that weakens between grant and buy-back makes the buy-back dearer, so the leg-by-leg gain shrinks, while a single conversion at the later rate grows it: the net method overstates this gain by £2.90 at the real rate and by £15.25 at $1.25. At the real rates the tax on £100.52 is £18.09 at 18% or £24.12 at 24%, assuming the £3,000 exempt amount is used by other gains. HMRC prescribes no source for the rate; the tax page discusses which sources hold up.

Holding a dollar balance changes when conversions happen, not this computation: each leg is still converted at its own date's rate. Each firm's charge for converting pounds into dollars is on the broker page.

Margin minimums and day trading after FINRA 26-10

A US margin account at a FINRA member firm needs, under FINRA Rule 4210(b)(4), "equity of at least $2,000 except that cash need not be deposited in excess of the cost of any security purchased". That is £1,475.04 at the model rate. It is a rule for US broker-dealers, not a Regulation T figure and not a UK rule.

Writing options does not always need a margin account. The Federal Reserve's Regulation T allows a firm to sell an option for a customer in a cash account "as part of a covered option transaction" (12 CFR 220.8(a)(3)), which is how covered calls and fully cash-secured puts are written in cash accounts. Uncovered writing and most spreads need a margin account and a higher permission level; the levels, and how they differ by firm, are on the Level 1 page and in the broker matrix.

The pattern day trader rule, which designated a margin account making four or more day trades in five business days and required USD 25,000 of equity (£18,437.94), has been replaced. FINRA Regulatory Notice 26-10 swaps the designation and the minimum for intraday margin standards from 4 June 2026, and lets firms take until 20 October 2027 to implement the change. Some firms still apply the old count during the phase-in: Interactive Brokers' own account table, checked on 26 September 2026, still describes the USD 25,000 requirement for accounts that remain under the old rules. A firm's current margin page is the record for a given account.

What opening a US options account involves

• A knowledge check or an approval. An FCA-authorised firm must run the appropriateness test before a retail client trades options (COBS 10A); a failed test brings a warning, not a ban (basics page). A US broker-dealer works under FINRA Rule 2360(b)(16): it gathers the client's investment objectives, employment, income and net worth, a principal approves or refuses the account for options in writing, and the client signs an agreement within 15 days of approval.
• The options disclosure document. FINRA Rule 2360(b)(11): "Every member shall deliver the current ODD to each customer at or prior to the time such customer's account is approved for trading options." The document is Characteristics and Risks of Standardized Options.
• A permission level. Firms grant strategies in steps, from buying options only up to uncovered writing, and the steps differ: one UK route allows buying only, another stops before uncovered positions. See the broker matrix.
• The W-8BEN, signed at opening (above).
• Market data. Live US option quotes come from OPRA, which firms charge for or bundle. Interactive Brokers lists OPRA top-of-book data at USD 1.50 a month for a non-professional (£1.11, or £13.28 a year). Its published minimum balance for an individual account is USD 0.

On 6 April 2026 the FCA's consumer composite investments regime began to replace the PRIIPs key information document, with a transition to full go-live on 8 June 2027; derivatives are in scope, and from go-live a firm must not sell a product that lacks an up-to-date product summary to a retail client (FCA PS25/20). How that will be met for options listed in the US was not settled in the rules we read (checked 28 September 2026).

Splits, cash takeovers and adjusted US contracts

When a US company splits its shares, merges or pays an unusual dividend, an adjustment panel of the options exchanges, with one OCC representative who votes only to break a tie, decides whether and how listed options change. A two-for-one split doubles the number of contracts and halves the strike. A reverse split keeps the strike and the number of contracts but changes what each contract delivers, so a contract may no longer mean 100 shares. When a company is bought for cash, its options are generally adjusted to deliver a fixed amount of cash, and trading stops once the merger takes effect, so out-of-the-money options are worthless and in-the-money options lose their time value. OCC publishes each adjustment in an Information Memo, searchable by symbol (OIC corporate actions FAQ). The ICE equivalents are on the assignment page.

Who holds the account, and what protects it

The protection depends on which firm holds the assets, not on the app. Where an FCA-authorised firm holds them under UK client-asset rules, the FSCS can pay up to £85,000 per person if the firm fails. Where a US broker-dealer holds them, SIPC applies instead: "The limit of SIPC protection is $500,000, which includes a $250,000 limit for cash" (£368,759 and £184,379 at the model rate), and the FSCS does not cover those assets; a client who deals with the US firm directly also has no Financial Ombudsman route. Some UK-authorised firms introduce clients to a US custodian: IG's US options and futures account, for example, is executed by tastytrade and held at Apex Clearing, and IG and Robinhood UK each say in their own documents that the FSCS does not apply to the assets held with the US firm. Neither scheme covers a fall in value. The broker page sets out each firm's chain.

The records a UK return needs from each US trade

How these become SA108 entries is on the Self Assessment page.

Model inputs and sources