You have found a tired terrace, the sums look tempting on the back of an envelope, and one question matters before you commit: after the higher stamp duty and the tax on your profit, does a flip in 2026 leave enough to justify the risk? Here is the model.
Two costs decide most flips
Everyone budgets for the refurbishment. Fewer people budget properly for the two costs that quietly eat the margin:
- Stamp duty with the 5% surcharge. Because a flip is almost always an additional property, you pay the higher rate. The additional-property surcharge rose from 3% to 5% on 31 October 2024 (gov.uk), and the standard nil-rate band dropped back to £125,000 from 1 April 2025.
- Income tax on the profit, not capital gains tax. This surprises people, and it changes the answer.
Why a flip is taxed as income, not capital gains
If you buy a property intending to sell it on at a profit, HMRC generally treats that as a trade, not an investment. The test is the "badges of trade": your intention when you bought, how long you held the property, whether you changed the asset in order to sell it, and how often you do this sort of thing (HMRC sets this out in its Business Income Manual).
A buy-renovate-sell project ticks most of those boxes. So the profit is taxed as trading income at your income tax rate, not the gentler CGT rates of 18% or 24% on residential property. You also do not get the CGT annual exempt amount, and a sole trader may owe Class 4 National Insurance on top.
That single distinction can cost thousands, so it belongs in the model from the start, not as an afterthought at the year end.
A worked 2026 flip
These figures are an illustrative example, not a market average. Swap in your own deal.
| Item | Amount |
|---|---|
| Purchase price | £200,000 |
| Stamp duty (5% surcharge included) | £11,500 |
| Legal and survey on purchase | £1,800 |
| Refurbishment | £35,000 |
| Finance, roughly 9 months | £11,000 |
| Holding costs (council tax, insurance, utilities) | £2,500 |
| Selling costs (agent plus legals) | £6,000 |
| Sale price | £300,000 |
| Pre-tax profit | £32,200 |
Pre-tax profit here is the sale price less the purchase price and every cost above it.
The stamp duty
On a £200,000 additional property, the 5% surcharge sits on top of the standard residential bands:
- £0 to £125,000 at 5% = £6,250
- £125,000 to £200,000 at 7% = £5,250
- Total = £11,500
That is £11,500 gone before a single wall is painted. You can check the exact figure for any purchase price, surcharge included, with our stamp duty calculator before you make an offer.
The tax on the profit
Pre-tax profit is £32,200. Compare the two ways it could be taxed:
- As trading income (correct for most flips), higher-rate 40%: about £12,880, leaving roughly £19,300 before any National Insurance.
- As a capital gain at 24% (what people often assume): about £7,728 after the £3,000 annual exemption.
The income-tax treatment costs around £5,000 more on this one deal. An additional-rate taxpayer at 45% keeps even less.
So, is it worth it?
On these numbers you turn roughly £267,800 of committed money, plus nine months of work and risk, into about £19,300 after tax. That is a real profit, but the margin is thin, and it assumes:
- the refurbishment lands on budget,
- the property sells near the asking price, and
- rates and holding costs do not drift while you hold.
Miss the sale price by 5% (£15,000), or overrun the refurb by £10,000, and the after-tax profit halves or worse. Flipping in 2026 works, but mainly where you buy well below market and control the build tightly.
Ways the maths can improve
- Buy further below market. The margin is made on the purchase, not the sale.
- Watch the finance clock. Bridging can cost 0.75% to 1% a month, so every extra month of delay shows up directly on the profit line.
- Consider a limited company. A company pays corporation tax (19% up to £50,000 of profit, 25% above £250,000, with marginal relief between) rather than your personal income tax rate, though extracting the cash is then taxed again. Whether it helps depends on your wider position, so take advice.
- Uninhabitable properties are contested ground. Some genuinely derelict buildings have been argued to fall outside the surcharge, or even outside residential rates, but HMRC has narrowed this and the case law is unsettled, so do not bank on it.
The takeaway
A 2026 flip has to clear two hurdles many spreadsheets miss: a 5% stamp duty surcharge on the way in, and income tax, not capital gains tax, on the way out. Model both from the first offer. If the deal still shows a worthwhile margin after that, it can stack up. If it only works by assuming CGT rates or by ignoring the surcharge, it does not.
This is general information, not tax or financial advice. Property trading tax is fact-specific, so confirm your own position with a qualified accountant before you commit.
