How Is CGT Calculated When You Sell Multiple Properties in the Same Tax Year?

Selling more than one property in a single tax year changes the capital gains tax arithmetic in ways that catch a lot of landlords out. The instinct is to treat each sale as its own self-contained event with its own allowance. It is not. HMRC pools every disposal you make in the year into one calculation, hands you a single annual exempt amount across the lot, and then taxes the combined gain against your income. Get the timing wrong and you can pay thousands more in tax than the same sales would have cost spread over two tax years.

This guide sets out exactly how the calculation works when you dispose of several properties together, where the pressure points are, and the planning levers that genuinely move the number. The headline facts for 2026/27: one £3,000 annual exempt amount for the whole year, residential gains taxed at 18% or 24%, and a separate 60-day report due for each property where tax is payable.

One Tax Year, One Allowance: How the Gains Are Pooled

The single most important rule is that the annual exempt amount is per person, per tax year, not per property. Whether you sell one buy-to-let or six in 2026/27, you deduct £3,000 once. There is no splitting it across disposals and no carrying forward the unused part to a later year.

The mechanics run in a fixed order. You calculate the gain on each property separately, add them together, set current-year losses and then brought-forward losses against the total, deduct the single £3,000, and tax what remains. Take a landlord selling three properties in 2026/27 with gains of £15,000, £8,000 and £12,000. The pooled gain is £35,000. They deduct one £3,000, not £9,000, leaving £32,000 in charge. The deeper mechanics of the relief sit in our guide to the £3,000 CGT annual exempt amount.

What trips people up is the assumption that smaller sales escape because each gain looks modest. They do not. A £4,000 gain in isolation would be almost wiped out by the allowance, but bundle it with two larger gains in the same year and the whole £4,000 is exposed, because the £3,000 has already been spoken for by the pool.

Why Aggregation Pushes You Toward the 24% Rate

Capital gains do not have their own tax bands. They sit on top of your income and use whatever is left of your basic-rate band, which runs up to £50,270 for 2026/27. The slice of gain inside that band is taxed at 18%; everything above it at 24%, under the residential rates set by s.1H TCGA 1992. Those rates have applied to residential property since 30 October 2024.

This is where bundling disposals hurts. The basic-rate band is a fixed-size bucket each year. Sell one property and a chunk of the gain may fall in the 18% band. Sell four together and the first gains fill the band, leaving the rest stacked entirely at 24%. You have not changed the size of the gains, only compressed them into a single year where the 18% band can only stretch so far.

Consider a higher earner with £60,000 of employment income, so the basic-rate band is fully used before any gain is counted. Every pound of property gain that year is taxed at 24%. The same landlord in a year out of work, or after retiring, might have £20,000 of basic-rate band free, taxing the first slice of gain at 18%. Same property, very different bill, driven entirely by which year the sale completes in.

Worked Example: Four Disposals, One Year Versus Two

Picture a landlord winding down a portfolio with four properties, each carrying a £30,000 gain, so £120,000 of gains in total. They are a higher-rate taxpayer with income above £50,270, so their basic-rate band is used up by income alone.

All four in 2026/27. Pooled gain £120,000, less one £3,000 allowance, gives £117,000. With no basic-rate band free, the whole £117,000 is taxed at 24%, a CGT bill of £28,080.

Two in 2026/27, two in 2027/28. Each year: £60,000 of gains, less a £3,000 allowance, gives £57,000 taxed at 24%, so £13,680 a year, £27,360 across the two years. The saving is £720, the value of the second annual exempt amount at 24%.

Now change one fact. Suppose in 2027/28 the landlord has stopped working and has £20,000 of unused basic-rate band. In that year £20,000 of the £57,000 is taxed at 18% rather than 24%, saving a further £1,200. The total saving from spreading climbs to £1,920, and it grows further if income is low in both years. The lesson is consistent: spreading creates fresh allowances and fresh 18% headroom, and the benefit scales with how much basic-rate band you can free up.

Factor	All disposals in one tax year	Disposals spread across years
Annual exempt amount used	One £3,000 across the whole portfolio	£3,000 per tax year you sell in
Access to the 18% band	Single year's basic-rate headroom only	Fresh basic-rate headroom each year
Typical effective rate	Skewed toward 24% as the band fills	More gain held at 18% across years
60-day reporting	One report per taxable disposal, clustered	One report per taxable disposal, staggered
Market and void risk	Exit completed quickly	Exposed to price and tenancy changes between sales
Cash flow	Proceeds and tax all land together	Proceeds and tax phased

The table makes the trade-off plain. Spreading is a tax win but it is not free: you carry market and tenancy risk for longer, and a sale you assumed would slip into the next tax year can complete early and undo the plan. Timing is driven by completion dates, not exchange or marketing dates, so build in a margin around the 5 April line.

Using Losses Across a Cluster of Sales

When you sell several properties together, a loss on one is genuinely useful rather than a write-off you absorb alone. Current-year losses are set against current-year gains automatically and in full before the annual exempt amount, so a £10,000 loss on one disposal reduces the taxable pool on the profitable ones pound for pound.

Brought-forward losses behave more carefully. They are used only down to the level of the annual exempt amount, so the £3,000 is never wasted against a loss you could have saved. If you have older losses sitting in reserve, a year in which you crystallise large gains is exactly when to deploy them. The detail of claiming and carrying losses is covered in our guide to claiming capital losses on property, and you must report a loss to HMRC, normally within four years of the end of the tax year, to be able to use it.

Spreading Ownership Across a Spouse or Civil Partner

Spouses and civil partners are taxed independently, so each has their own £3,000 annual exempt amount and their own basic-rate band. On a jointly held portfolio that effectively doubles the allowance available in any year and gives two 18% bands to fill before the 24% rate bites.

Transfers between spouses happen at no gain, no loss under s.58 TCGA 1992, meaning the receiving spouse simply inherits the original base cost with no CGT on the transfer itself. Moving a share of a property to a lower-earning spouse before a sale can shift gain into their unused basic-rate band and pick up a second allowance. This needs to be a genuine beneficial transfer made before completion, not a paper exercise after the fact, and the practical steps are set out in our note on transferring property to a spouse before sale.

The 60-Day Reporting Trap With Clustered Sales

Each residential disposal on which CGT is due needs its own return and payment through HMRC's UK Property service within 60 days of that property's completion. The clock runs from each completion separately, so three sales completing across a fortnight create three 60-day deadlines, not one. With several disposals close together this is where compliance slips, because the deadlines stack up while the figures are still being finalised.

Where a disposal produces no CGT, because losses, the annual exempt amount or Private Residence Relief cover it, a UK resident does not need to file the 60-day return for that property. Non-residents are treated differently and must report every UK land disposal regardless of whether tax is due. All disposals, reportable or not, are then reconciled on your Self Assessment return, and any 60-day payments are credited against the final figure. Our guide to CGT payment deadlines on property sales sets out the calendar in full, and the underlying gain calculation is walked through step by step in our CGT calculation guide for selling a buy-to-let.

Devolved Taxes Do Not Touch CGT, But They Touch Timing

CGT is a UK-wide tax: there is no Scottish or Welsh variant, so the 18% and 24% residential rates apply wherever the property sits. What does differ is the purchase-side tax your buyers face and any reinvestment you make. In Scotland that is Land and Buildings Transaction Tax plus the Additional Dwelling Supplement; in Wales it is Land Transaction Tax with its higher residential rates. These do not change your CGT, but if you are recycling sale proceeds into replacement stock, the acquisition cost in a devolved nation feeds your next disposal's base cost and can shape which year you choose to buy and sell.

Section 24 and the Retain-Versus-Sell Decision

For many landlords the reason multiple properties are going on the market at once is the cumulative weight of Section 24. With mortgage interest now relieved only as a 20% basic-rate tax credit rather than a deduction, geared higher-rate landlords are taxed on rental profit they do not fully keep, and the effect compounds across a portfolio. We cover the mechanics in our guide to claiming mortgage interest relief under Section 24.

From 6 April 2027, separate property income tax rates of 22%, 42% and 47% take effect, enacted by Finance Act 2026 and applying across England, Wales and Northern Ireland, with only Scotland carved out for 2027/28. Crucially, the Section 24 reducer rises to 22% in step with the new basic rate, so no fresh basic-rate wedge opens for property income. These rates fall on rental profit, not on capital gains, so your CGT on disposal is unaffected. They do tilt the retain-versus-sell sum for higher earners, which is part of why some landlords are choosing to exit now rather than hold. The interaction with disposals is explored in our note on how the 2027 property tax rates affect CGT on sales.

Selling the Portfolio Versus Incorporating It

A full disposal is not the only way out of a portfolio under pressure. Transferring the properties into a limited company is an alternative some landlords weigh, but it is not a CGT-free shortcut. Moving a property into a company is a disposal at market value for CGT, and it usually triggers SDLT on the deemed purchase. Incorporation relief under s.162 TCGA 1992 can defer the gain where a genuine property business is transferred wholly or mainly in exchange for shares, but the bar for what counts as a business, and the SDLT exposure, both need careful checking before anyone commits. A company also has no £3,000 annual exempt amount, paying corporation tax on its gains instead.

The honest framing is that selling and incorporating answer different questions. Selling suits a genuine exit; incorporation suits a landlord who wants to keep investing on a more efficient long-term footing. Our buy-to-let limited company guide works through the company route, and for those who want to keep the asset but defer the gain, our note on CGT deferral strategies for property investors covers the available reliefs.

A Practical Sequence for Disposing of Several Properties

Before any contracts go out, the planning is mostly arithmetic done in advance. Map each likely completion to a tax year, estimate the gain on each property, identify which years you can free up basic-rate band by managing other income, and decide whether spouse ownership should be rebalanced first. Then stress-test the plan against the risk that a sale completes earlier or later than hoped, because a single completion sliding across 5 April can move a £30,000 gain between two rate environments.

The reliefs and the rate structure are fixed; the variable you control is timing and ownership. That is where the saving lives, and it is why portfolio disposals reward planning done months ahead rather than in the conveyancing endgame.

Where Specialist Advice Earns Its Place

Multiple disposals are exactly the scenario where modelling pays for itself, because the difference between a one-year clear-out and a phased exit can be several thousand pounds, and the right answer depends on numbers specific to you: the spread of gains, your income in each candidate year, available losses, and whether a spouse can absorb part of the gain. A specialist property accountant can build that model, confirm the 60-day obligations on each sale, and make sure the wider picture is right, especially if you are a non-resident landlord with reporting duties on every disposal or you are weighing incorporation against an outright sale. The full policy context sits in our complete guide to capital gains tax on property.