Buy-to-Let UK 2026: Is It Still Worth It?

The Buy-to-Let UK market is not what it was a decade ago. Between Section 24's mortgage-interest tax change, three rounds of stamp duty surcharges, the abolition of wear-and-tear allowance, the renters' rights reforms, and 2022-2024 mortgage rate spikes, the after-tax economics for a typical leveraged landlord have collapsed compared to 2015.

This guide does the maths in 2026/27 numbers. We will work through what BTL actually returns once tax and costs are stripped out, how it compares to a global index fund, and the specific situations in which BTL still genuinely makes sense.

Contents

• How Section 24 changed BTL forever
• The real after-tax yield in 2026
• Stamp duty on a second property
• BTL vs a global tracker: the comparison
• When BTL still makes sense
• The hidden costs people forget
• Frequently asked questions

How Section 24 Changed BTL Forever

Until 2017, individual landlords could deduct mortgage interest from rental income before tax was calculated. Earn £15,000 in rent, pay £8,000 in interest, and you were taxed on £7,000.

Section 24 of the Finance Act 2015 (phased in 2017-2020) replaced that deduction with a 20% tax credit. Now you are taxed on the full £15,000 of rent, then HMRC gives you a flat 20% credit on the £8,000 of interest. The difference is brutal for higher-rate taxpayers:

For a higher-rate taxpayer, the same property now pays roughly 50% more tax than it used to. For an additional-rate taxpayer it is worse. Limited-company structures dodge Section 24 (companies still get full interest deduction) but introduce their own tax frictions on extracting profit.

The Real After-Tax Yield in 2026

Take a representative leveraged BTL purchase in 2026:

• Property value: £250,000
• Deposit: £62,500 (25%)
• Mortgage: £187,500 at 5.5%
• Annual rent: £15,000 (6% gross yield)
• Annual interest: £10,313
• Letting agent fee (10%): £1,500
• Maintenance, insurance, void allowance: £1,500
• Service charge / ground rent (if leasehold): £500
• Net rental income before tax: £1,187

For a higher-rate taxpayer, applying Section 24:

• Tax on £15,000 at 40% = £6,000
• Less 20% credit on £10,313 interest = -£2,063
• Net tax: £3,937

After-tax annual cash return: £1,187 - £3,937 = -£2,750

The leveraged landlord is paying almost £3,000 a year out of pocket on the income side. The investment only "works" if capital appreciation exceeds that loss. House prices have averaged ~3.5% per year over the long term; on a £62,500 deposit that is £8,750 of paper appreciation, against £2,750 of cash drag and the opportunity cost of the deposit. The after-tax IRR works out to around 4-6% on most leveraged BTL purchases at 2026 mortgage rates - and that is before maintenance shocks (boilers, roofs, void months between tenants).

Basic-rate taxpayers do better because Section 24 hurts them less, but the leverage ratios are still tighter than they were before 2017.

Stamp Duty on a Second Property

When you buy any property other than your main home, you pay an extra 5% stamp duty surcharge (raised from 3% in October 2024) on top of normal SDLT bands. On a £250,000 BTL purchase that is an extra £12,500 in stamp duty alone, before the standard SDLT.

The full SDLT bill on a £250,000 second property in 2026/27:

That's a 6% transaction cost, recovered from rental cash flow only after years. Use the stamp duty calculator to model your specific purchase.

BTL vs a Global Tracker: the Comparison

For the same £62,500 deposit invested in a global equity tracker inside a Stocks and Shares ISA, over 25 years:

• Average historical real return: ~7%
• Compound to: £339,000

For the same £62,500 used as a BTL deposit:

• After-tax IRR: ~4-6% on a leveraged property (best case 2026 numbers)
• Compound to: £165,000-£268,000 of equity in the property
• Minus maintenance, void months, and the ongoing tax drag

The ISA wins on most plausible scenarios, by a wide margin, with no tenants to manage and no maintenance shocks. The reason BTL was attractive in 2010 was leverage - 4x leverage on the deposit meant any property appreciation was magnified. Section 24 and 5% stamp duty have stripped much of that advantage out.

When BTL Still Makes Sense

A few specific situations still tilt the maths back:

1. Basic-rate taxpayer with low or paid-off mortgages. Section 24 hurts most when interest is high and tax band is high. A landlord at basic-rate with a 50% LTV mortgage can still extract reasonable cash flow.
2. HMOs (Houses in Multiple Occupation). Yields on HMOs are typically 8-12% gross, well above standard BTL. The management workload is higher and licensing rules tighter, but the maths can work.
3. Limited company structures for higher earners. Buying through a company avoids Section 24 (the company gets full interest deduction). This trades higher SDLT and corporation tax friction for cleaner ongoing economics. Worth modelling for £500k+ portfolios.
4. Cash purchase, no mortgage. If you have £250k of cash, a BTL with no leverage produces 4-5% net yield with capital appreciation on top. Still arguably worse than a global tracker in a GIA, but the diversification away from equity may be valuable to some portfolios.
5. Investment near where you live, with lifestyle reasons. A holiday let, a future retirement home rented out for 10 years first, or a student property near a university you have local knowledge of. The financial case is no longer the headline; the lifestyle case carries it.

For everyone else, paying off your own mortgage faster or filling your ISA is almost always the better deployment of the same capital in 2026.

The Hidden Costs People Forget

When someone tells you they "make 8% from BTL", check whether they are counting:

• 6% gross yield on the headline rent
• Minus 1-2% letting agent fees and admin
• Minus 1-2% maintenance and insurance
• Minus 0.5-1% void allowance (4-6 weeks per 5 years)
• Minus mortgage interest (currently ~5-6% on the borrowed portion)
• Minus Section 24 tax effect at their marginal rate
• Minus 5% stamp duty surcharge spread over the holding period
• Minus 24% Capital Gains Tax on the eventual sale

The number you started with rarely survives all eight subtractions intact.

Frequently Asked Questions

Is buy-to-let still profitable in the UK in 2026?

For most higher-rate taxpayers buying with a mortgage, the after-tax cash flow is now negative or close to zero, and the case relies entirely on capital appreciation. For basic-rate taxpayers, low-leverage purchases, HMOs, or limited-company structures, BTL can still work. For everyone else, a global tracker in an ISA is usually the better return-per-pound.

How does Section 24 affect higher-rate landlords?

Section 24 stops landlords from deducting mortgage interest before tax. Instead they get a flat 20% tax credit on interest paid. For a higher-rate taxpayer this typically increases tax owed by 40-60% compared to pre-2017 rules. It does not apply to limited companies, which is why many landlords have incorporated since 2017.

What is the stamp duty surcharge on a second home in 2026?

5% on top of standard SDLT bands, raised from 3% in October 2024. On a £250,000 second home this is £12,500 of surcharge plus £2,500 of standard SDLT, for a total of £15,000.

Should I buy through a limited company for buy-to-let?

It depends on portfolio size and tax position. Limited companies dodge Section 24 (full interest deduction), pay corporation tax on profits, and you pay further tax extracting money as dividends or salary. The structure typically wins for higher-rate landlords planning to hold long-term and reinvest, and loses for landlords who want immediate access to rent income or have small portfolios.

Are house prices going to keep rising?

Probably, but not at the 7-8% per year that defined 2000-2020. Real (inflation-adjusted) UK house price growth has been roughly 2-3% per year over a century. Most plausible 25-year forecasts assume something in that range. BTL economics today require capital appreciation to do most of the work, which is a more uncertain bet than the rental yield was a decade ago.