Open the HMRC policy paper on the tax treatment of cryptoasset loans and liquidity pools, published on 13 July 2026, and scroll to the section headed Exchequer impact and... There is nothing in it.
The table is empty, and the accompanying text explains why: the costing is subject to scrutiny by the Office for Budget Responsibility and will be set out at a future fiscal event.
That is usually the standard formula for a measure announced ahead of its certification. But it does mean something specific, and it is the thing almost every piece of coverage since July has skipped: the government has told us what it intends to do, and has not yet told us what it costs. Until it does, the measure is a proposal with a commencement date attached, not a settled part of the tax system.
The future fiscal event now has a date. Wednesday 28 October 2026.
This article explains what happens on that day, why it matters more than usual this time, what a narrowing of either measure would actually look like, and what to do in the ten weeks between now and then.
What was announced, and what is still missing
Two measures landed on 13 July 2026, both targeted at Finance Bill 2026-27, both with an intended effect from April 2027.
Cryptoasset loans and liquidity pools: draft legislation amending the Taxation of Chargeable Gains Act 1992 to introduce no gain, no loss treatment for three defined arrangement types: Single Cryptoasset Lending Arrangements, Single Cryptoasset Borrowing Arrangements, and Automated Market Making Arrangements. It applies to individuals and trustees, takes effect from 6 April 2027, and HMRC estimates it affects around 700,000 people.
Stablecoins: the outcome of the call for evidence, setting out an intention to treat eligible stablecoins more like money. For individuals and trustees, disposals of eligible stablecoins become exempt from Capital Gains Tax from 6 April 2027, and interest like returns move into the savings income rules. For companies, from 1 April 2027, eligible stablecoins are treated as a money debt within the loan relationship rules. HMRC estimates around 1.2 million individuals are affected.
Both are draft and both are in technical consultation. And neither has a certified cost.
That last point deserves emphasis because of what these measures actually are. The lending measure is a deferral: it moves the tax point without reducing the total charged over the life of a position, so its cost to the Exchequer is largely a timing effect. The stablecoin measure is an exemption: disposals of eligible stablecoins simply fall out of the Capital Gains Tax computation altogether. Those are very different fiscal animals, and the second one is considerably more expensive to score.
What actually happens on 28 October
- 1
The Chancellor delivers the Budget.
- 2
The OBR publishes its Economic and fiscal outlook.
- 3
Every measure gets scored.
- 4
The tax documents are published.
Why this Budget carries more uncertainty than usual
Three factors compound here, and it is worth being precise about them rather than speculative.
John Healey did not author the July measures. First Budgets are traditionally where a Chancellor establishes priorities, and priorities are established as much by what is trimmed as by what is announced. In setting the date, the Chancellor framed the Budget as being built on fiscal discipline and meeting the fiscal rules.
The measures were developed under a previous administration and were four years in the making, from the 2022 call for evidence through the 2023 consultation to the summary of responses at Budget 2025. Long-gestation measures usually survive a change of personnel, because the policy work is sunk and the industry expectation is set. But "usually" is not "always", and no one should treat continuity as guaranteed.
This is the substantive point. Where a costing is already certified and published, a measure is difficult to unpick because the number is in the forecast. Where the box is blank, the number is still being negotiated. A relief whose cost has never been signed off is the easiest kind to narrow, because narrowing it does not require reversing anything the government has already banked.
None of that is a prediction. The most likely outcome, on the balance of how these processes usually run, is that both measures proceed broadly as published. The point is that "broadly" is doing work in that sentence, and the details that could move are precisely the details that determine whether the relief reaches you.
What narrowing would actually look like
Vague warnings are not useful. Here are the specific pressure points in each measure, and what a scope reduction would mean in practice.
On the stablecoin exemption
The eligibility definition. As published, eligible stablecoins are defined as cryptoassets maintaining a stable value in relation to a particular fiat currency, with fiat currency or other assets held to support that value. The phrase is currency neutral, which is why dollar denominated coins appear to be in scope, and that reading is supported by the consultation record: respondents said overwhelmingly that non-sterling coins had to be included because they dominate actual UK usage.
Restricting the relief to sterling denominated coins would be the single cheapest way to reduce its cost. It would also, on the industry's own evidence, leave the relief with very little to do.
The meaning of "other assets". Whether crypto collateralised or yield bearing tokens fall inside the backing test is unresolved. Tightening this is a smaller saving but an easier one to justify, since a token that functions as an investment fund is arguably outside the payments rationale for the relief.
There is also a coherence problem the government will have to answer. Holding foreign currency is not exempt from Capital Gains Tax for an individual outside limited circumstances. A dollar stablecoin held across a period of sterling weakness can produce a genuine sterling gain from the exchange rate alone. Exempting that while taxing the equivalent gain on a dollar bank balance is a difference that will be noticed, and one of the ways to resolve it is to narrow the exemption.
On the lending and liquidity measure
- 1
Which arrangements qualify. HMRC has signalled that the boundaries, particularly for less conventional automated market maker structures, are still being refined. A tighter definition of an Automated Market Making Arrangement would remove a share of the 700,000 from the relief without touching the headline.
- 2
Transitional treatment. The policy paper is silent on positions entered before 6 April 2027 and closed after it. That silence has to be resolved somewhere, and how it is resolved determines the treatment of a large stock of existing positions.
- 3
Commencement. Deferring a start date by a year is the least visible way to reduce a measure's cost inside a forecast period. It is also the change that would most directly affect anyone planning around April 2027.
- 4
Companies. The measure covers individuals and trustees only. Corporate alignment has been raised repeatedly and would be a natural extension. It has a cost, which makes an extension less likely in a discipline-framed Budget than in a giveaway one.
The other things a Budget can move
The two crypto measures are not the only reason 28 October matters to a UK crypto investor. Several general parameters feed directly into every crypto computation, and all of them are Budget decisions.
Capital Gains Tax rates. Currently 18% to the extent your income leaves room in the basic rate band, and 24% above it. These rates changed mid year as recently as October 2024, which required splitting the tax year for disposals either side of the change. It can happen again.
The Annual Exempt Amount. Currently £3,000, down from £12,300 three years ago. It shelters the first slice of total gains each year and its trajectory has been consistently downward.
Income tax bands and thresholds. Crypto income stacks on other income. Band movements change what a staking or lending reward actually costs, and they change the boundary between the 18% and 24% capital gains rates, which is set by your income.
The trading and miscellaneous income allowance. Currently £1,000, and the allowance most crypto lenders actually rely on, given that the Personal Savings Allowance does not apply to crypto returns until the stablecoin measure takes effect.
Reporting thresholds. The requirement to complete the capital gains pages where total disposal proceeds exceed £50,000 catches active traders regardless of whether they made a gain. Thresholds like this move at Budgets without attracting headlines.
Any one of these can change the arithmetic on a return more than the crypto specific measures do, and they take effect on their own timetables rather than in April 2027.
What to do before, on, and after the day
Before: do not restructure a portfolio on the strength of draft clauses. The three things most likely to move are the eligibility definition, the qualifying arrangement boundaries and the commencement date, and all three determine whether a given plan works. If you have a live concern about how a specific arrangement or coin is treated, raise it in one of the two windows that close in early September rather than waiting to see what happens.
Keep filing on the current basis: nothing that happens on 28 October changes the return due by 31 January 2027, which covers 2025/26 under the existing rules. Every stablecoin swap in that year is a disposal. Every DeFi deposit is analysed on beneficial ownership principles. The reforms, if they proceed, are not retrospective.
On the day: three things to look for, in order of importance. First, whether the two measures appear on the scorecard at all, and with what cost. Second, whether the eligibility definition or the qualifying arrangement definitions have changed from the July text. Third, whether the commencement dates have moved.
After: whatever emerges, the underlying data requirement does not change. Base cost, acquisition dates, sterling valuations at the right moments, correct classification of every movement. That requirement exists under the current rules and under every version of the proposed rules. It is the one part of this that is not contingent on 28 October.
Finbooks: ready for whatever comes next in investment tax
Whatever happens on 28 October, the underlying requirement stays the same: you need a complete transaction history that can support the tax treatment that ultimately applies.
Every plausible outcome on 28 October changes which rule applies to a transaction. None of them changes what you need to know about the transaction.
Whether a stablecoin disposal turns out to be exempt or chargeable, you need its date, its sterling value, its cost basis and its matching position. Whether a pool entry is a disposal or a no gain, no loss event, you need the quantities in, the quantities out, the entry value and the entry date. Whether commencement lands in April 2027 or a year later, you need to be able to apply one treatment to the transactions on one side of the line and a different treatment to those on the other.
That is what Finbooks is built to hold. Reconstructing activity across exchanges, wallets, protocols and chains. Valuing every disposal and every income event in sterling on the correct date. Applying the UK's own matching order, same day, then thirty day, then section 104 pool, rather than a generic method borrowed from another jurisdiction. Carrying cost basis coherently across tax years and across a commencement boundary, so that a deferral or an exemption can actually be claimed rather than merely being available in principle.
Three consequences worth stating plainly.
A date boundary is a computational rule, not a setting. Applying a new treatment retroactively across a whole history is the easy implementation and the wrong one. Positions that span a commencement date need both analyses available.
Classification decides the outcome, and classification is per transaction. Whether an arrangement is a Single Cryptoasset Lending Arrangement, an Automated Market Making Arrangement, or none of the three, and whether a coin meets the eligibility definition, determines the treatment. That is a decision made against each movement, not against each platform.
Uncertainty is an argument for better records, not worse ones. The less settled the rules, the more valuable it is to hold data that can be recomputed under whichever version arrives.
Uncertainty is an argument for better records, not worse ones. The less settled the rules, the more valuable it is to have a complete investment history that can be recalculated when those rules are settled. That is the position Finbooks is designed to keep you in.
