Writing in Professional Adviser on 12 August 2026, Andrew Aldridge argued that capital gains tax has long sat behind income tax and inheritance tax in the hierarchy of client concern — treated as occasional, relevant only when someone sells a business, realises gains in a portfolio or disposes of an investment property, and rarely the starting point for an advice relationship. The standfirst adds that the sharpest sense of grievance may now be among business owners. That is a fair reading of how the tax has been perceived. What makes it worth an accountant's attention is that the perception is now several years out of date, and the profession most exposed to the lag is ours.
Here is the uncomfortable shape of it. The accountant is the person who computes the gain — and, in the ordinary run of a tax year, computes it somewhere between nine and twenty-two months after the disposal happened. By the time the figure appears on a computation, every decision that could have changed it has already been made: which tax year the contract completed in, whose name the asset was in, whether the disposal was taken in one bite or two. CGT is therefore the most retrospective tax an accountancy practice handles, and the one where the gap between when a firm sees something and when it could have done something about it is widest.
What actually changed, and when
Three separate movements have compounded, and it is the compounding rather than any single change that has altered the character of the tax.
The allowance. HMRC's rates and allowances guidance, last updated on 13 April 2026, records an annual exempt amount of £3,000 for individuals in 2026-27 and £1,500 for most trustees. It was also £3,000 in 2025-26 and 2024-25, £6,000 in 2023-24, and £12,300 in both 2022-23 and 2021-22. That is a fall of just over 75% in four tax years.
The main rates. GOV.UK sets the rates for gains made from 6 April 2026 at 18% within the basic rate band and 24% above it, with 24% for trustees and personal representatives. Those were 10% and 20% for most assets until 29 October 2024.
Business Asset Disposal Relief. GOV.UK's BADR guidance is explicit: 18% on qualifying gains disposed of from 6 April 2026, 14% between 6 April 2025 and 5 April 2026, and 10% on or before 5 April 2025. Investors' Relief tracks the same path. The relief still exists; what it is worth has changed sharply, three years running.
Individually, each of those is a line in a Budget summary. Together they mean that a client population which used to fall outside CGT entirely now files, and a client population which used to treat a 10% exit charge as a rounding item is meeting something considerably heavier.
The £15,000 gain that now costs 5.3 times more
Take a higher-rate taxpayer who realises £15,000 of gains on a share portfolio — not an unusual figure for a director tidying up a holding, and precisely the sort of disposal that used to be barely worth a paragraph.
- In 2022-23: the annual exempt amount was £12,300, leaving £2,700 chargeable. At the then main higher rate of 20%, the tax was £540.
- In 2026-27: the annual exempt amount is £3,000, leaving £12,000 chargeable. At 24%, the tax is £2,880.
Identical gain, identical asset, identical client. The bill is 5.3 times larger, and — this is the part that matters operationally — the second version of that client has a reporting obligation where the first version did not. Multiply that across a portfolio of owner-managed clients and the January workload has changed shape without anybody deciding it should.
The business sale that got 80% more expensive in two years
The BADR movement is starker still, because it lands on the single largest transaction most clients will ever make. Consider a shareholder disposing of qualifying trading company shares with a £1m gain, fully within the BADR lifetime limit:
- Completion on or before 5 April 2025: 10% — £100,000.
- Completion between 6 April 2025 and 5 April 2026: 14% — £140,000.
- Completion from 6 April 2026: 18% — £180,000.
An £80,000 difference on the same transaction, driven by nothing but the date on the completion statement. A client who formed a mental picture of their exit proceeds in 2024 and has been carrying it around since is holding a number that is now £80,000 out. Very few of them will have revised it, because nobody sent them a letter about it. Their accountant is the professional best placed to notice that the number in their head no longer matches the number on the page.
CGT is not a tax you advise on at the deadline. By the deadline it is arithmetic. The advice happened, or failed to happen, months earlier.
Who is actually paying it — and why that matters
HMRC's Capital Gains Tax statistics are accredited official statistics; the most recent edition was updated on 24 July 2025. Four figures from it are worth an accountant's attention.
First, scale: in 2023-24 the total CGT liability was £12.1bn, arising for 378,000 taxpayers on £65.9bn of gains. Second, breadth: HMRC attributes a 1% rise in taxpayer numbers that year to the allowance cut from April 2023, which it estimates brought up to 87,000 additional taxpayers into the scope of the tax. That is a lot of people meeting a tax return for a reason they did not anticipate.
Third, and most useful of all, age. HMRC reports that the 55 to 64 age group has consistently had the most CGT taxpayers and, together with the 45 to 54 group, accounts for the largest gains and liabilities — those two groups represented 45% of the CGT-liable population and contributed around 60% of the gains and tax in 2023-24. Read that alongside The lang cat's State of Advice Report 2025, which puts the average IFA client age at 59, and the overlap is almost exact. The people realising the gains are the people at the point in life where a financial plan either exists or conspicuously does not.
Fourth, BADR volume: 39,000 taxpayers claimed it in 2023-24 on £10.3bn of gains, producing £1bn of liabilities and 8% of all CGT. Those 39,000 are, overwhelmingly, somebody's accountancy client — and each one represents a business owner who has just converted an illiquid asset into cash.
Property: sixty days, not ten months
The property side deserves separate mention because its timetable is the one that catches firms out. GOV.UK requires CGT due on a UK residential property disposal to be reported and paid within 60 days of completion, through a Capital Gains Tax on UK property account, with interest and a penalty possible for late reporting.
HMRC's statistics show 163,000 taxpayers filing a CGT on UK Property return in 2024-25, covering 183,000 disposals and £10.3bn of gains for £2.2bn of tax — the highest figures since the service was introduced in April 2020. Sixty days from completion is not a long window in which to discover that a client sold a flat, establish the base cost, agree the reliefs and file. It is a great deal shorter than the interval between the client selling and the client mentioning it.
The lever that closes at completion
This is where the two professions genuinely interlock, and where the case for a joined-up conversation stops being an abstraction.
Almost everything that changes a CGT outcome is a pre-disposal decision. The tax year the disposal falls into. Whether it is phased across two years to use two annual exempt amounts. How the asset is held between spouses or civil partners before a sale. Whether losses elsewhere are crystallised in the same year. And — the one that sits squarely on the boundary between the two disciplines — where the client's taxable income sits relative to the basic rate limit, because that is what determines whether a slice of gain is charged at 18% or 24%.
GOV.UK's own worked example makes the boundary concrete. A taxpayer with £20,000 of taxable income and £52,600 of gains in 2026-27 deducts the £3,000 allowance to leave £49,600. Because the basic rate band is £37,700, £17,700 of the gain is charged at 18% and £31,900 at 24%, producing £10,842. Move that boundary — and relief on a personal pension contribution extends the basic rate limit by the gross amount contributed — and gain moves from the 24% column to the 18% column at 6p in the pound. A £10,000 gross contribution shifts £10,000 of gain across that line: £600 of CGT, before any consideration of the income tax relief on the contribution itself.
Whether that is the right thing for any particular client is emphatically a regulated question, and not one for an accountancy practice to answer. But noticing that the two calculations are connected, and that they are connected before completion rather than after it, requires no permissions at all. It requires somebody to be looking at both halves at the same time — which is the practical argument for accountants and financial planners talking to each other while a transaction is still hypothetical. We set out where the dividing line usually falls in accountant and financial planner: who does what, and what it looks like around a sale in the joined-up exit.
Two things worth doing this week
1. Run a completion-date query across live deals. Any client with a business sale, share disposal or investment property sale in progress has a date that is now worth £40,000 per £1m of qualifying gain at each step of the BADR path. Where a transaction is still being negotiated, the tax consequence of the timing is a fact worth putting in front of the client in writing, even if the timing itself is outside their control. Some clients will already know. The ones who do not tend to be the ones who set their expectations in 2024.
2. Pull the list of clients whose gains sat between £3,000 and £12,300. These are the clients who fell outside CGT under the old allowance and inside it now. It is a mechanical query against last year's data and it produces a genuinely useful client communication: not a sales letter, but a short note explaining that a threshold moved and that a disposal they would previously have ignored now needs recording. It is also, incidentally, the most reliable way of discovering which of your clients hold portfolios and property you did not know about.
Both of those are ordinary practice management. Neither requires anybody to sell anything. What they produce is a list of clients for whom the next twelve months contain a decision — and that list is the same list a financial planner would want, which is precisely the point. The broader case is in the six signals already sitting in your client file, and the underlying numbers on advice coverage are on the advice gap.
What is still uncertain
Two things, and it is worth being straight about both.
The allowance and the rates set out above are what GOV.UK states for 2026-27, as updated on 13 April 2026. Whether the £3,000 annual exempt amount persists beyond this tax year is a Budget matter and is not addressed in current guidance, so any client conversation about future years should be framed on the position as it stands rather than an assumed continuation of it.
The evidence base also has a lag. HMRC's CGT statistics were last updated on 24 July 2025, and their main tables run to 2023-24 — which means the full-year effect of the 18% and 24% rates on total liabilities and taxpayer numbers has not yet appeared in that series. The property tables already run to 2024-25 and are showing record volumes. The next annual update of the publication is where the rest of the picture becomes visible, and it will be the first hard evidence of whether higher rates have changed disposal behaviour or merely the size of the cheques.
Common questions
What is the Capital Gains Tax annual exempt amount for 2026-27?
For the 2026 to 2027 tax year the annual exempt amount is £3,000 for individuals, personal representatives and trustees for disabled people, and £1,500 for most other trustees. That is the same figure as 2025-26 and 2024-25. Before that it was £6,000 for 2023-24, and £12,300 for both 2022-23 and 2021-22, so the individual allowance has fallen by just over 75% in four tax years. HMRC publishes the full table in its Capital Gains Tax rates and allowances guidance, last updated on 13 April 2026. The practical consequence for a firm is that gains which never previously reached a tax return now do, and modest portfolio and property disposals have become reportable events rather than rounding errors.
What rate does Business Asset Disposal Relief charge now?
Business Asset Disposal Relief charges 18% on qualifying gains disposed of from 6 April 2026. It charged 14% on qualifying disposals between 6 April 2025 and 5 April 2026, and 10% on qualifying disposals on or before 5 April 2025. Investors’ Relief follows the same rate path. Those figures come from GOV.UK’s Business Asset Disposal Relief guidance and its rates and allowances table. On a £1m qualifying gain the tax has therefore moved from £100,000 to £140,000 to £180,000 across three consecutive tax years, without the relief itself being withdrawn. For any client whose exit sits inside that window, the completion date now carries a materially different price tag from the one they may have assumed.
How quickly does a residential property gain have to be reported?
Capital Gains Tax due on a UK residential property disposal must be reported and paid within 60 days of completion, using a Capital Gains Tax on UK property account. GOV.UK states that interest and a penalty may follow if the report and payment are late, and that clients already in Self Assessment must also include the disposal in their return. This is the deadline most likely to catch a firm out, because it runs from completion rather than from the tax year end, and the client rarely thinks to mention a sale until the annual accounts conversation. HMRC recorded 163,000 taxpayers filing property returns in 2024-25, the highest figure since the service opened in April 2020.
At what point in a disposal is it too late to plan?
Most of the levers that affect a capital gain operate before the disposal happens, not after it. Which tax year the disposal falls into, whether it is phased across more than one year, how assets are held between spouses or civil partners beforehand, and whether pension funding shifts income across the basic rate boundary in the same year are all decisions made in advance. Once contracts have exchanged and completion has taken place, the computation is largely arithmetic. That is why a gain first discussed at the January filing deadline is usually a gain that has already been fixed, and why the useful conversation is the one held when the client first mentions they are thinking about selling.
Which CGT conversations belong with an accountant and which with a financial planner?
The computation, the reporting, the reliefs claimed on the return and the qualifying conditions attaching to them are accountancy and tax work. What the client should do with the proceeds afterwards — how they are invested, whether pension funding forms part of the picture, how the money supports an income once the business has gone — involves regulated advice and sits with an authorised firm. The two overlap at the point where a disposal is still being contemplated, because the tax position and the financial plan inform each other. Working out who does which part in advance is usually more useful to the client than either professional deciding alone after the event.