Specialist US UK Tax Services: Land Overage and Options

An American who sells UK land with an overage clause, or grants an option over it, faces two tax systems that time the same gain differently. HMRC values the contingent right at the sale date and taxes it upfront; the IRS generally spreads the gain as cash arrives. Specialist US UK tax services reconcile both returns.

At Jungle Tax we prepare the US and UK returns for American landowners whose sale price is not yet known on completion day. This guide explains, in return-preparation terms, how each country treats overage (clawback) payments, option premiums and promotion agreements, where the two sets of rules collide, and what has to be reported, on which form, and when. It deals with land only. A contingent price on the sale of a company is a different computation with different reliefs and is not covered here.

What are overage, option and promotion agreements?

Development land is rarely sold for a single fixed sum. Three arrangements dominate, and each produces a different tax event.

• Overage (clawback). The landowner sells now for an initial price and is entitled to a further payment if a trigger occurs later, typically the grant of planning permission, the sale of completed units above a set value, or an onward sale of the site. The amount usually depends on figures that do not yet exist.
• Option agreement. A developer pays a premium for the right, but not the obligation, to buy the land within a set period, often at a price fixed by a formula once planning permission is obtained. The landowner keeps the land unless and until the option is exercised.
• Promotion agreement. A promoter funds and pursues planning permission, the land is then marketed, and the promoter takes a fee, normally a percentage of the eventual proceeds. The landowner remains the seller throughout.

For a US citizen or green card holder, every one of these is reportable to both HMRC and the IRS, because the United States taxes its citizens on worldwide gains wherever they live and the UK taxes gains on UK land whoever owns it.

How does HMRC tax an overage payment on a land sale?

Ascertainable or unascertainable: the first question

The UK computation turns on whether the deferred amount can be worked out at the date of disposal.

• Ascertainable consideration is an amount that is known, or can be calculated from facts existing at the sale date, even if payment is postponed or conditional. A fixed further sum payable if planning permission is granted is ascertainable. The whole amount is brought into the capital gains computation at the outset, with no discount for delay or for the risk that the condition is never met. If part later proves irrecoverable, the computation is adjusted by claim.
• Unascertainable consideration depends on events that have not yet happened, for example a percentage of the uplift in value on a future planning consent, or a share of sale prices not yet achieved. HMRC's guidance confirms that a cap on the total does not make the amount ascertainable.

The Marren v Ingles principle: two assets, two disposals

Where the overage is unascertainable, the House of Lords decision in Marren v Ingles governs. The right to the future payment is a separate chargeable asset (a chose in action). The seller is treated as receiving two things on completion: the cash, and that right. HMRC's Capital Gains Manual applies the principle expressly to land at CG72850. The consequences for the return are:

• First disposal, at the sale date. The consideration for the land is the cash received plus the market value of the overage right on that date. Capital gains tax is due on that total, even though nothing has been received for the right.
• Second disposal, when the overage is received. Each receipt is a disposal, or a part disposal, of the right. The base cost of the right is the value that was taxed in the first computation. If the overage exceeds that value, a further gain arises; if it falls short, or never materialises, there is a loss. HMRC sets this out at CG14970.

The valuation of the right is therefore central. It should be a reasoned figure, supported by a professional valuation that reflects the probability and timing of the trigger event, and it should be retained with the return papers. HMRC may refer the figure to its own valuers. Because a date of disposal for capital gains purposes is normally the date an unconditional contract is made, not the completion date, the sale can also fall into an earlier UK tax year than the seller expects.

HMRC's guidance also indicates that the statutory facility to pay capital gains tax in instalments, which can apply where a fixed price is paid over a long period, is not regarded as appropriate for unascertainable deferred consideration. In practice the tax on the valued right falls due on the normal dates.

If the overage disappoints: the section 279A loss election

A loss on the right would ordinarily arise in the later year and could only be carried forward. Sections 279A to 279D of the Taxation of Chargeable Gains Act 1992 allow an individual, subject to conditions and a statutory time limit, to elect for that loss to be treated as arising in the earlier year in which the gain on the original land disposal was taxed. The result is a reduction of the earlier year's gain and, usually, a repayment of UK tax. HMRC's guidance begins at CG15080. The election is a compliance matter with a deadline, and, as explained below, a UK repayment of this kind has a direct US filing consequence.

Option premiums and section 144

Under section 144 of the 1992 Act, the grant of an option is the disposal of an asset, namely the option itself, and not a part disposal of the land. The premium is therefore a chargeable receipt in the UK tax year of grant, generally with no part of the land's cost available to set against it. What happens next depends on the outcome:

• Option exercised. The grant and the sale are treated as a single transaction. The premium is added to the sale price in one computation for the year of the sale, and the earlier stand-alone computation on the grant is withdrawn or adjusted.
• Option lapses or is abandoned. The grant remains a completed disposal for the landowner and the tax on the premium stands.

Under a promotion agreement there is usually no disposal until the land is actually sold. The promoter's fee is then generally deductible as an incidental cost of the disposal, provided it was incurred wholly and exclusively for that purpose.

Can HMRC tax an overage payment as income instead?

Yes, in some cases. The transactions in UK land rules (Income Tax Act 2007, sections 517A to 517U, in force from 5 July 2016) can treat a profit as trading income rather than a capital gain where land is acquired or developed with a main purpose of realising a profit from its disposal, and they can reach a landowner whose price is linked to the proceeds of someone else's development. HMRC's own guidance says the rules should be considered wherever a land sale provides for further consideration on a future event. A payment geared solely to the grant of planning permission is less likely to be caught than a share in the developer's eventual sale proceeds, and the gain attributable to the period before development was first intended is generally left within capital gains tax. Which regime applies is a question of fact on the contract, and the return must reflect the correct one because the rates, the forms and the US credit position all follow from it.

60-day reporting

Separately from the Self Assessment return, a UK resident disposing of UK residential property with tax to pay must generally file a UK property return and make a payment on account within 60 days of completion. A non-UK resident must generally report any direct or indirect disposal of UK land, residential or not, within the same period, whether or not tax is due. Bare agricultural land sold by a UK resident will not usually trigger the 60-day return, but land with a dwelling on it, or a sale by a non-resident American, may. The reporting route is set out at GOV.UK. Americans who live outside the UK should also note that non-residents have been within UK capital gains tax on residential land since April 2015 and on all UK land since April 2019, with rebasing rules for earlier ownership.

How does the IRS tax the same sale?

Contingent payment sales under the installment method

For US purposes, a sale in which at least one payment is received after the end of the tax year of sale is an installment sale, and the installment method applies automatically unless the taxpayer elects out. Where the total price cannot be determined by the end of the year of sale, the sale is a contingent payment sale, governed by Temporary Regulation section 15a.453-1(c). The gain is recognised as payments are received, and the regulation prescribes how the seller's basis is recovered:

• Stated maximum selling price. If the contract caps the total, the cap is treated as the selling price. Basis is spread against that maximum, and the computation is revised if it later becomes clear that the maximum will not be reached.
• No maximum, but a fixed payment period. Basis is generally allocated in equal annual amounts to the tax years in which payments may be received. If a year's payment is less than that year's basis allocation, no loss is allowed (other than in the final year); the unused basis carries forward.
• Neither a maximum nor a fixed period. Basis is generally recovered in equal amounts over 15 years, and the arrangement is examined to confirm that it is a sale at all.

Installment sale income is computed on Form 6252, filed for the year of sale and for each later year in which a payment is received, with the capital gain carried to Schedule D. The IRS's general explanation is in Publication 537. Where the installment method does not apply, the sale is reported on Form 8949 and Schedule D.

Electing out, and why "open transaction" treatment is rarely available

A seller may elect out of the installment method on a timely filed return for the year of sale. The gain is then computed in full for that year, and the regulations require the contingent right to be valued and included in the amount realised, with a floor: its value is treated as not less than the value of the land sold less the other consideration received. That produces a US result broadly resembling the UK's first disposal. The alternative sometimes suggested, the open-transaction doctrine under which nothing is taxed until basis has been fully recovered, is confined by the regulations to rare and extraordinary cases in which the right genuinely cannot be valued. A right that has just been professionally valued for HMRC is difficult to describe to the IRS as incapable of valuation. Whether to elect out is a reporting decision with consequences in both countries, and it must be made by the due date, including extensions, of the return for the year of sale.

Imputed interest under sections 483 and 1274

Overage clauses almost never carry interest. US law does not accept that. Where a deferred payment under a sale contract carries no adequate stated interest, part of it is recharacterised as interest. For a contingent payment, the interest element is generally measured when the payment is made, by discounting it back to the sale date at the applicable federal rate. That slice is ordinary interest income, not capital gain, and it reduces the selling price for Form 6252 purposes. There is no UK equivalent in the capital gains computation, so the two returns will show different amounts of gain on the same receipt. Very large deferred obligations can also attract a separate interest charge on the deferred tax under section 453A where the taxpayer's installment obligations arising in the year exceed 5 million US dollars.

Option premiums: held open until exercise or lapse

The US treatment of an option premium is the reverse of the UK's. The premium is not taxed on receipt. It is held in suspense until the option is exercised or lapses:

• On exercise, the premium is added to the amount realised on the sale of the land and takes the character of that gain.
• On lapse, the premium is recognised in the year of lapse. For an option over land it is generally ordinary income, because the rule in section 1234(b) that treats a grantor's gain as short-term capital gain is limited to options over securities and commodities.

Character, holding period and sterling

Land held as an investment for more than one year produces long-term capital gain, and installment gain keeps the character fixed at the date of sale. Gain on land held for sale to customers, or used in a farming business, follows different rules and needs separate analysis. The 3.8% net investment income tax can apply to the gain and to the imputed interest, and under the Internal Revenue Code it is generally not reduced by foreign tax credits.

The US return is prepared in dollars. Basis is translated at the exchange rate when the land was acquired and improved, and each sterling payment is generally translated at the spot rate on the day it is received. A seller can therefore show a different dollar gain from the sterling gain reported to HMRC, and a right to deferred sterling may give rise to separate currency gain or loss, a point reviewed case by case.

UK and US treatment compared

Issue	UK (HMRC)	US (IRS)
Unascertainable overage at sale	Right valued and taxed upfront as part of the land consideration	Installment method by default; gain recognised as payments arrive
Later overage receipt	Second disposal of the right; gain or loss against the value already taxed	Further installment gain after basis recovery; part recharacterised as interest
Overage never paid	Capital loss on the right; section 279A election can carry it back to the sale year	Unrecovered basis generally allowed only in the final payment year; no carryback for individuals
Fixed but conditional sum	Ascertainable: full amount taxed at sale, adjusted by claim if not received	Still a contingent payment sale if the price is not determinable at year end
Option premium	Taxed in the year of grant; merged with the sale if exercised	Held open; taxed on exercise (as sale proceeds) or lapse (generally ordinary income)
Interest element	None imputed in the capital gains computation	Imputed under sections 483 or 1274
Possible income treatment	Transactions in UK land rules	Dealer property and ordinary income rules; character set by US law
Main forms	Self Assessment capital gains pages; 60-day UK property return where required	Form 6252, Form 8949, Schedule D, Form 1116
Tax year	6 April to 5 April	Calendar year

Where the two systems collide: foreign tax credit timing

The US-UK income tax treaty allows the UK to tax gains on UK land and, through its saving clause, leaves the US free to tax its citizens on the same gain. Double taxation is relieved by the US foreign tax credit, claimed on Form 1116. A gain on UK real property is foreign source, so in principle the UK tax is creditable. The difficulty is timing.

• UK tax first, US gain later. The UK charges tax on the valued right in the year of sale. Under the installment method the US has not yet recognised that part of the gain. The credit is limited each year to the US tax on foreign-source income in the relevant category, so UK tax paid in the sale year can exceed the limitation.
• Carryback and carryover. Unused foreign tax can generally be carried back one year and forward ten. In many overage cases the excess from the sale year is absorbed when the overage is finally received and the US recognises the larger share of the gain. That only works if the carryover is tracked accurately on each year's Form 1116.
• Paid or accrued. An individual may claim the credit for the year foreign tax is paid, or elect to claim it for the year it accrues. The election, once made, applies to all later years. Because the UK tax year ends on 5 April, the choice determines which US calendar year receives the credit.
• Section 905(c) redeterminations. If UK tax that has been credited is later refunded, the US credit must be redetermined. A section 279A election does exactly this: it reopens the UK sale year and produces a repayment. The taxpayer must then notify the IRS and file an amended US return for the affected year. Omitting this step is one of the most common errors we see when earlier years are reviewed.
• Option premiums. The UK taxes the premium in the year of grant; the US taxes it years later, on exercise or lapse. If the option is exercised, the UK computation is itself revised, so the UK tax attributable to the premium may move between years as well.
• Character differences. If the UK taxes the receipt as income under the transactions in UK land rules while the US treats it as capital gain, the credit is still computed under US rules, but the UK tax will be higher than a capital gains computation would have produced and the limitation needs careful modelling.

Worked example (hypothetical figures)

The following illustration uses round, invented numbers and ignores exchange-rate movements, selling costs, allowances and the imputed interest element so that the timing difference is visible. It is not a computation for any real case.

A US citizen resident in England bought a field some years ago for 200,000 pounds. In June 2026 she sells it to a developer for 600,000 pounds on completion plus an overage of a share of the uplift if residential planning permission is granted before the end of 2030. There is no cap. A valuer puts the overage right at 500,000 pounds at the sale date.

If the overage is paid

Planning permission is granted and 800,000 pounds is received in 2028.

• UK, 2026/27: consideration 1,100,000 pounds (600,000 cash plus 500,000 right) less cost of 200,000 gives a gain of 900,000 pounds.
• UK, 2028/29: 800,000 received less the 500,000 base cost of the right gives a further gain of 300,000 pounds.
• US, 2026: no maximum price but a fixed period, so basis is spread equally over the five tax years 2026 to 2030, 40,000 a year. Gain reported is 600,000 less 40,000, or 560,000.
• US, 2027: no payment; the 40,000 of basis for the year carries forward.
• US, 2028: 800,000 received less 80,000 of basis gives 720,000, with the remaining 80,000 of basis taken into account as the agreement concludes.

Both countries tax a total gain of 1,200,000 pounds. But the UK taxes 900,000 of it in the first year against 560,000 for the US. UK tax in the sale year is likely to exceed the US limitation, creating a carryover that is used in 2028, when the US gain is much larger than the UK's.

If the overage is never paid

Planning permission is refused and the right expires worthless at the end of 2030.

• UK: a loss of 500,000 pounds arises on the right. With a valid section 279A election it is treated as arising in 2026/27, reducing that year's gain from 900,000 to 400,000 and generating a repayment.
• US: only 40,000 of basis was recovered in 2026. The remaining 160,000 is generally allowed as a loss in the final payment year, 2030. An individual cannot carry a capital loss back, so the 2026 US gain of 560,000 stands, even though the true economic gain was 400,000.
• Foreign tax credit: the UK repayment for 2026/27 triggers a section 905(c) redetermination of the credit originally claimed, and an amended US return.

The second scenario is where returns most often go wrong: the UK position is corrected, the US position is not, and the two filings no longer agree.

What records and filings does an American landowner need?

• The sale contract, overage deed, option or promotion agreement, with every trigger date diarised.
• Acquisition and improvement costs with dates, so that basis can be translated into dollars at historic rates.
• The professional valuation of the overage right at the sale date, and at each part disposal if payments come in tranches.
• Evidence of intention and of any involvement in the development, relevant to the transactions in UK land rules.
• The UK Self Assessment return, any 60-day UK property return, and the section 279A election if a loss arises.
• Form 6252 for the sale year and each payment year, Form 8949 and Schedule D, and Form 1116 with a carryover schedule.
• FBAR and Form 8938 reporting for the UK accounts that receive the proceeds. Directly held land is not itself reportable on Form 8938, but whether a contractual right against a non-US counterparty is a reportable asset should be considered each year.

What if earlier years were not reported correctly?

We regularly see Americans in the UK who reported an overage sale to HMRC and never told the IRS, or who reported the cash to the IRS but omitted the option premium, the imputed interest, or the section 905(c) adjustment after a UK repayment. Others have never filed a US return at all. Where the failure was non-wilful, the IRS streamlined procedures may allow the missing returns and FBARs to be brought up to date; our IRS streamlined filing team prepares those submissions. On the UK side, an omitted valuation of the overage right or a missed 60-day return is corrected by amendment or disclosure through our UK tax services. In each case the work is the same: reconstruct the transaction, compute it correctly under both systems, and file returns that agree with each other.

How Jungle Tax prepares these returns

Our US-UK tax accountants prepare both countries' returns from a single set of working papers, so the valuation used for HMRC, the basis schedule on Form 6252 and the credit carryover on Form 1116 are consistent from the sale year to the final overage payment. Through our US tax services we also maintain the multi-year schedules that a contingent payment sale requires, so that nothing is lost between one year's return and the next. We prepare and file returns; we do not design or market sale structures.

If you are a US citizen or green card holder who has sold, or is about to sell, UK land with an overage, option or promotion agreement, or you suspect an earlier sale was reported in only one country, please contact our cross-border team to arrange a confidential consultation. We will review the agreement, set out what each return needs to show, and prepare the filings accurately in both jurisdictions.