New Build Property Investment Tax Guide for UK Landlords
Published by New-Builds Team • Tax & Investment Guide • 22 min read
Taxation is arguably the single most significant factor determining the profitability of UK property investment, yet it remains one of the least understood aspects of being a landlord. The UK tax landscape for property investors has undergone dramatic changes since 2016, with the phased introduction of Section 24 mortgage interest restrictions, increases to Stamp Duty Land Tax surcharges, reforms to Capital Gains Tax rates and reporting requirements, and evolving rules around allowable expenses. For landlords investing in new build properties, understanding how these taxes interact — and how they can be legally minimised through proper structuring and planning — is the difference between a portfolio that generates genuine wealth and one that merely services its tax obligations. HMRC collected over £12 billion in property-related taxes from individual landlords in the 2023-2024 tax year, a figure that underscores both the scale of the tax burden and the importance of getting your tax affairs right from the outset.
This comprehensive guide examines every tax that affects UK property investors in the 2025-2026 tax year, from the moment you purchase your first new build investment property through to the day you sell it. We cover Income Tax on rental profits, Capital Gains Tax on disposal, Stamp Duty Land Tax on acquisition, the mechanics and impact of Section 24, the tax implications of limited company ownership versus personal ownership, every category of allowable expense you can claim, and practical strategies for legally reducing your overall tax burden. Whether you own a single buy-to-let or are building a multi-property portfolio, this guide provides the knowledge you need to make informed decisions and keep more of the returns your properties generate.
2025-2026 Tax Rates at a Glance
Before diving into the detail, here is a summary of the key tax rates and thresholds that apply to property investors in the 2025-2026 tax year (6 April 2025 to 5 April 2026).
Income Tax on Rental Profits
Rental income from investment properties is taxable as property income under the Income Tax Act 2007. For individual landlords (those who own properties in their personal name), rental profits are added to your other income (employment, self-employment, pensions, etc.) and taxed at your marginal rate. This means that if your employment income already places you in the higher-rate band, every pound of rental profit is taxed at 40% or even 45%.
Your taxable rental profit is calculated as follows: total rental income minus allowable expenses equals taxable profit. For individual landlords, mortgage interest is no longer an allowable expense (see Section 24 below) but is instead treated separately as a tax credit. All other legitimate property expenses remain fully deductible.
Worked Example: Income Tax on Rental Profit (2025-2026)
Scenario: Higher-rate taxpayer with employment income of £60,000. Owns one new build apartment generating £12,000 annual rent.
| Gross Rental Income | £12,000 |
| Less: Allowable Expenses (exc. mortgage interest) | -£3,200 |
| Taxable Rental Profit | £8,800 |
| Income Tax at 40% (higher rate) | £3,520 |
| Less: Section 24 Tax Credit (20% of £5,400 mortgage interest) | -£1,080 |
| Net Income Tax on Property | £2,440 |
Effective tax rate on rental profit: 27.7%. Without Section 24 (if full mortgage interest deductible): £1,360 tax (15.5% effective rate). Section 24 cost to this landlord: £1,080 per year.
Section 24: The Mortgage Interest Restriction Explained
Section 24 of the Finance (No. 2) Act 2015 is widely regarded as the most impactful tax change for UK landlords in a generation. Introduced by then-Chancellor George Osborne and phased in between April 2017 and April 2020, it restricts the ability of individual landlords to deduct mortgage interest costs from their rental income. Understanding how it works — and how to mitigate its impact — is essential for every property investor.
Before Section 24, individual landlords could deduct their full mortgage interest payments from their rental income before calculating their tax liability. This meant that a property with £12,000 rent and £6,000 in mortgage interest would be taxed on only £6,000 of profit (before other expenses). Section 24 removed this deduction entirely. Now, the full £12,000 of rent is added to your taxable income, and you receive only a basic-rate (20%) tax credit for the mortgage interest paid.
The Hidden Danger of Section 24
Section 24 can push landlords into a higher tax band even when their actual cash profit has not increased. Because the full rental income (without mortgage interest deduction) is added to your other income for tax purposes, it can push you from the basic rate into the higher rate, or from the higher rate into the additional rate. In extreme cases, it can also trigger the loss of your Personal Allowance (which is reduced by £1 for every £2 of income above £100,000), creating an effective marginal rate of 60% on income between £100,000 and £125,140. This phantom income problem means you could be paying tax on money you never actually received.
The impact of Section 24 varies dramatically depending on your tax rate and leverage level:
For a higher-rate taxpayer with £100,000 in total mortgage debt at 5% interest (£5,000 annual interest), Section 24 costs an additional £1,000 per year compared to the pre-2017 regime. Across a portfolio of five leveraged properties, this could easily amount to £4,000-6,000 in additional annual tax. This is the primary reason that many portfolio investors have moved to limited company structures for new acquisitions.
Stamp Duty Land Tax (SDLT) for Investment Properties
Stamp Duty Land Tax is the upfront tax payable on the purchase of property in England and Northern Ireland (Scotland has LBTT; Wales has LTT). For investment property purchases, the standard SDLT rates are increased by a 5% surcharge on each band — a significant acquisition cost that must be factored into every investment appraisal.
The surcharge was increased from 3% to 5% in the Autumn Budget of October 2024, representing a substantial increase in the upfront cost of acquiring investment properties. This 5% surcharge applies to any residential property purchase where the buyer already owns one or more residential properties (with limited exceptions for replacement of a main residence).
SDLT Calculation Examples (Additional Property Rates)
SDLT on investment properties purchased through a limited company is calculated using the same additional property rates. Companies always pay the surcharge on residential purchases, regardless of whether they own other properties. The SDLT is payable within 14 days of completion and must be reported via an SDLT return filed with HMRC.
Capital Gains Tax on Property Disposal
When you sell an investment property for more than you paid for it (after allowable costs), the profit is subject to Capital Gains Tax. For individual landlords, the CGT rates on residential property gains are 18% for basic-rate taxpayers and 24% for higher-rate and additional-rate taxpayers (2025-2026 tax year). The Annual Exempt Amount has been reduced to £3,000, meaning only the first £3,000 of your total capital gains in any tax year are tax-free.
Your taxable gain is calculated as: Sale price minus purchase price, minus allowable purchase costs (SDLT, legal fees, survey costs), minus allowable improvement costs (but not repairs), minus selling costs (estate agent fees, legal fees), minus your Annual Exempt Amount. The resulting figure is then taxed at 18% or 24% depending on your income level.
CGT Worked Example
| Sale Price | £250,000 |
| Original Purchase Price | -£185,000 |
| Purchase Costs (SDLT, legal, survey) | -£12,500 |
| Selling Costs (agent, legal) | -£5,500 |
| Gross Gain | £47,000 |
| Less: Annual Exempt Amount | -£3,000 |
| Taxable Gain | £44,000 |
| CGT at 24% (higher-rate taxpayer) | £10,560 |
60-Day CGT Reporting Requirement
Since April 2020, UK residents must report and pay CGT on residential property disposals within 60 days of the completion date. This is done via a Capital Gains Tax property disposal return submitted through your HMRC online account. Late filing results in automatic penalties starting at £100, with interest charged on late payment. This is separate from your annual Self Assessment return, though the gain must also be reported on your tax return for the year in which the sale took place.
For properties owned within a limited company, there is no CGT. Instead, the profit on sale is subject to Corporation Tax at 19-25%. There is also no Annual Exempt Amount for companies. However, the company may benefit from indexation allowance for gains that accrued up to December 2017, and the overall tax rate on gains can be lower than the 24% CGT rate for higher-rate individual taxpayers.
Allowable Expenses: What You Can (and Cannot) Claim
Claiming all legitimate allowable expenses is one of the most effective ways to reduce your tax bill. HMRC allows landlords to deduct expenses that are incurred wholly and exclusively for the purpose of the rental business. For new build properties, the expense profile differs somewhat from older properties, particularly in the early years when maintenance costs tend to be lower but other costs (such as furnishing and initial letting) can be significant.
Allowable Expenses
Non-Allowable Expenses
Note: Purchase costs and improvements are instead deductible from capital gains when you sell the property.
Repairs vs Improvements: The Critical Distinction
HMRC draws a clear line between repairs (allowable as a revenue expense) and improvements (capital expenditure, not deductible from rental income). A repair restores something to its original condition — for example, replacing a broken boiler with a similar model, repainting walls, or fixing a leaking roof. An improvement enhances the property beyond its original state — for example, adding an extension, converting a loft, or replacing single-glazed windows with double glazing. For new build properties, most early expenditure tends to be covered by the builder’s warranty, but when repairs are needed, ensure they are classified correctly to maximise your deductions.
Limited Company vs Personal Ownership: Full Tax Comparison
The question of whether to hold investment properties personally or through a limited company is the most consequential tax decision a UK property investor will make. The answer depends on your specific circumstances, but here is a detailed comparison to help frame the analysis.
The break-even point between personal and company ownership varies by individual circumstance but typically favours a limited company when: (a) you are a higher-rate or additional-rate taxpayer, (b) you plan to use leverage of 60% LTV or above, (c) you intend to retain profits within the business for portfolio growth rather than drawing them as income, and (d) you are building a portfolio of three or more properties. For more on structuring your portfolio for growth, see our guide on financing multiple investment properties.
Incorporation: Transferring Properties to a Company
If you already hold properties personally and wish to transfer them to a limited company, this process is known as incorporation. It is complex, potentially costly, and requires careful professional advice. The key tax implications of incorporation include:
Capital Gains Tax
Transferring a property from your personal name to a company is treated as a disposal at market value for CGT purposes. You will owe CGT on any gain that has accrued since you purchased the property. However, if you are transferring an entire property business (not just individual properties), you may qualify for Incorporation Relief under Section 162 TCGA 1992, which allows CGT to be deferred.
Stamp Duty Land Tax
The company must pay SDLT on the market value of the properties being transferred, at the additional property rates (including the 5% surcharge). On a portfolio worth £500,000, this could amount to over £30,000 in SDLT alone. There is no SDLT relief for incorporation in most circumstances.
Section 162 Incorporation Relief
This valuable relief defers CGT when a sole trader or partnership transfers a business (not just assets) to a company in exchange for shares. To qualify, you must transfer the entire rental business as a going concern, including all assets and liabilities. The gain is rolled over into the base cost of the shares rather than being immediately taxable. This relief requires careful structuring and HMRC scrutiny, so specialist professional advice is essential.
Given the significant upfront costs, incorporation only makes financial sense when the long-term tax savings from company ownership outweigh the CGT and SDLT costs of transfer. For many landlords, a hybrid approach makes more sense: retain existing personally held properties and purchase all new acquisitions through a limited company, avoiding the transfer costs while benefiting from the more tax-efficient structure on future growth.
Tax Strategies for New Build Landlords
Within the boundaries of the law, there are several legitimate strategies that new build property investors can use to optimise their tax position.
If your spouse or civil partner pays tax at a lower rate than you, transferring a share of the property ownership to them can reduce the overall tax burden. Transfers between spouses are exempt from CGT and SDLT (provided there is no mortgage or the transfer is made with no consideration). The lower-earning spouse then declares their share of the rental income at their marginal rate. Note: the default HMRC assumption for jointly owned property is 50/50, unless you submit a Form 17 declaration of beneficial interest with evidence of unequal ownership.
Maintain meticulous records of every allowable expense. Many landlords fail to claim for travel costs (at 45p per mile for the first 10,000 business miles), professional body memberships (NRLA, etc.), property management software subscriptions, landlord insurance, and even a proportion of home office costs if you manage your portfolio from home. Over a tax year, unclaimed expenses of £500-1,500 are common, representing £200-675 in unnecessary tax for a higher-rate payer.
If you plan to sell an investment property, consider the timing in relation to the tax year. If your income is likely to be lower in a particular year (due to retirement, career break, or reduced hours), selling during that period could result in CGT being charged at 18% rather than 24%. Similarly, using your Annual Exempt Amount of £3,000 by disposing of properties in different tax years rather than the same year can save up to £720 per disposal.
While capital allowances are limited for residential property, landlords who furnish properties for letting can claim the Replacement of Domestic Items Relief, which allows the cost of replacing furnishings, appliances, and household items to be deducted from rental income (but not the initial cost of furnishing). Additionally, properties with qualifying integral features (such as certain types of heating systems) may qualify for capital allowances in a limited company structure.
Making Tax Digital for Income Tax
HMRC’s Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) programme will require landlords with annual gross property income above £50,000 to use compatible software to keep digital records and submit quarterly updates to HMRC from April 2026. Landlords with income between £30,000 and £50,000 will be brought into the regime from April 2027.
This represents a significant change in how landlords manage their tax affairs. Instead of filing a single annual Self Assessment return, you will need to submit updates every quarter (approximately every 3 months), maintaining digital records of income and expenses using HMRC-compatible software. While this adds administrative burden, it also encourages better record-keeping and more timely awareness of your tax position throughout the year.
Preparing for MTD
Start using digital record-keeping software now, even before MTD becomes mandatory for your income level. Popular options include FreeAgent, Xero, QuickBooks, and specialist property management software like Landlord Vision or Arthur Online. Getting comfortable with digital record-keeping before the requirement takes effect will make the transition much smoother and reduce the risk of errors or penalties. Your accountant can advise on the most suitable software for your portfolio size and structure.
Frequently Asked Questions
Can I offset rental losses against other income?
Rental losses can only be carried forward and offset against future rental profits from the same property business. They cannot be offset against employment income, self-employment income, or other types of income. If you make a rental loss in one year, it is carried forward automatically to reduce your taxable rental profit in future years. Note that since Section 24, it is possible to make a tax loss on property income (because the full rental income is taxed without mortgage interest deduction) even when your actual cash position is profitable — but this loss for tax credit carry-forward purposes has specific rules that your accountant can explain.
Do I need to register as self-employed to rent out a property?
Letting property as an individual does not make you self-employed in the traditional sense. However, you do need to register for Self Assessment with HMRC and declare your rental income on your annual tax return. You should register by 5 October following the tax year in which you first received rental income. Failure to register and declare can result in penalties and interest. Rental income is reported in the property income section of the tax return, not as self-employment income.
How much tax will I pay on a £200,000 buy-to-let apartment?
Tax is not based on the value of the property but on the rental profit it generates. For a £200,000 apartment generating £1,000 per month (£12,000 per year) with £3,500 in allowable expenses, the taxable profit is £8,500. A basic-rate taxpayer would pay £1,700 (20%) in income tax, while a higher-rate taxpayer would pay £3,400 (40%), offset by any Section 24 mortgage interest tax credit. In addition, you would have paid approximately £11,500 in SDLT on purchase (at additional property rates) and will pay CGT on any gain when you eventually sell.
Is there a way to avoid the 5% SDLT surcharge?
The 5% surcharge applies to most additional residential property purchases. The main exemption is if you are replacing your main residence (sold the old one and bought a new one) within 36 months. For investors, there is very limited scope to avoid the surcharge. Purchasing through a company does not help — companies always pay the surcharge. The surcharge is a legitimate cost of investment property acquisition that should be factored into your purchase price calculations and yield analysis from the outset.
Should I get a specialist property tax accountant?
Yes, this is strongly recommended for any investor with more than one or two properties, or for anyone using a limited company structure. Property tax is a specialist area that general accountants may not be fully across, particularly the nuances of Section 24, incorporation relief, CGT reporting, and the interaction between personal and company tax. A good property tax accountant typically saves several times their fee through optimised structuring, maximised expense claims, and proper compliance that avoids HMRC penalties.
Key Takeaway
Tax planning is not an afterthought — it should be integral to your property investment strategy from day one. The decisions you make about ownership structure, financing, expense management, and disposal timing can have a cumulative impact of tens of thousands of pounds over the life of your investment portfolio. Invest in specialist professional advice, maintain meticulous records, and review your tax position annually to ensure you are operating as efficiently as possible within the current legislative framework. For practical guidance on managing your properties tax-efficiently, see our guides on landlord responsibilities and property management for new build landlords.