I'm considering buying my first BTL property; does Section 24 mean I can't deduct any mortgage interest, and how does this affect my expected net rental income compared to pre-2017 rules?
Quick Answer
Section 24 restricts individual landlords from deducting mortgage interest from rental income, replacing it with a 20% tax credit. This reduces net income, especially for higher-rate taxpayers, compared to pre-2017 rules.
## Understanding the Impact of Section 24 on Buy-to-Let Mortgages
Section 24 of the Finance (No. 2) Act 2017 fundamentally altered how individual landlords can treat finance costs, including mortgage interest, against rental income. Since its full implementation in April 2020, landlords operating as individuals can no longer deduct mortgage interest and other finance costs when calculating their taxable property profits. Instead, a basic rate tax credit equivalent to 20% of their finance costs is provided. This change primarily impacts higher and additional rate taxpayers, as their actual tax relief on mortgage interest is now capped at 20%, rather than their marginal tax rate of 42% or 47% (from April 2027).
For example, if an individual landlord has £10,000 in annual mortgage interest and their rental income is £20,000, under the old rules, their taxable profit would have been £10,000. If they were a higher rate taxpayer, they would have paid 42% on this, or £4,200. Under Section 24, their taxable profit is assessed on the full £20,000 rental income. After paying 42% tax (£8,400), they would then receive a 20% tax credit on the £10,000 interest, which is £2,000. This leaves them with a net tax bill of £6,400, a significant increase from the pre-2017 figure.
### Does Section 24 Affect All Property Investment Structures?
Section 24 specifically targets individual landlords. Properties held within a limited company structure are not directly affected by Section 24. A limited company can still deduct all finance costs, including mortgage interest, as a business expense before calculating its taxable profits. Corporation Tax applies to these profits at a rate of 19% for profits under £50,000, or 25% for profits over £250,000, with marginal relief between these thresholds.
This distinction is why many new buy-to-let investors, and some existing ones, choose to hold their properties within a limited company, often referred to as a Special Purpose Vehicle (SPV). The tax efficiency for higher-rate taxpayers can be considerably better. However, holding properties in a company has its own complexities, including higher mortgage rates, company formation costs, and additional accounting requirements, which must be weighed against the tax benefits. According to HMRC guidance, the method of ownership dictates tax treatment.
### How Does Section 24 Impact Net Rental Income?
The primary impact of Section 24 on net rental income is a reduction for higher and additional rate taxpayers. Basic rate taxpayers (22% from April 2027) will find their tax liability broadly unchanged, as the 20% tax credit closely aligns with their marginal rate. However, those in higher tax brackets will see a considerable decrease in their post-tax income from property. For a higher rate taxpayer, the difference between deducting interest at 42% and receiving a 20% credit means an additional 22% of their interest costs become a true expense, not a tax-relievable one.
Consider a property generating £15,000 annual rental income with £8,000 in mortgage interest. Before Section 24, a higher-rate taxpayer would be taxed on £7,000 (£15k - £8k), paying £2,940 in tax (42%). After Section 24, they are taxed on £15,000, paying £6,300 (42%), then receive a £1,600 tax credit (20% of £8k), leaving a net tax bill of £4,700. This is an additional £1,760 in tax, directly reducing net rental income. This means the actual return on investment must be carefully modelled to ensure profitability under the current rules.
## Benefits of Holding Property in a Limited Company
* **Mortgage Interest Deductibility:** All finance costs, including mortgage interest, are fully deductible as a business expense, reducing taxable profit.
* **Corporation Tax Rates:** Profits are subject to Corporation Tax, which can be lower than higher individual income tax rates (19% for profits under £50k, 25% over £250k).
* **Income Splitting & Planning:** Greater flexibility for profit extraction and tax planning, potentially via dividends, which can be more tax-efficient than individual income for shareholders.
## Downsides of Limited Company Ownership
* **Higher Mortgage Rates:** Buy-to-let mortgages for limited companies often have slightly higher interest rates and arrangement fees compared to personal buy-to-let mortgages.
* **Company Formation & Accounting Costs:** Setting up and maintaining a limited company involves legal fees, annual accounts, and company secretarial duties, adding to overheads.
* **Lending Restrictions:** Some lenders have stricter criteria or fewer product offerings for limited company BTLs.
## Investor Rule of Thumb
Always model your property's profitability under both individual and limited company ownership, considering all income, expenses, and your personal tax position, before committing to a purchase.
## What This Means For You
Section 24 is a significant factor in buy-to-let investment profitability, particularly for those earning above the basic tax rate. Understanding its implications is crucial for accurate financial forecasting and choosing the right ownership structure. Inside Property Legacy Education, we provide the tools and understanding to calculate these scenarios precisely, helping you make informed decisions about whether to buy in a personal name or through a limited company. Most investors don't fail due to lack of effort, but due to a lack of accurate financial modelling and understanding the tax implications upfront.
Steven's Take
The shift with Section 24 was a game-changer for individual landlords, especially those in the higher tax brackets. When I started building my portfolio, these rules weren't in place, which meant direct interest deductibility was a given. Now, it's non-negotiable to consider a limited company structure for any new acquisitions, particularly if you're a higher-rate taxpayer. The 20% tax credit simply doesn't cut it for those paying 42% or 47% income tax. You need to crunch the numbers rigorously to see the true net return. Don't just assume what worked pre-2017 still applies. The margins are tighter, and tax efficiency is paramount.
What You Can Do Next
Consult a qualified property tax accountant: Discuss your personal income and the specifics of your potential investment to determine the most tax-efficient ownership structure (personal vs. limited company).
Model your net rental income: Use a detailed spreadsheet to project rental income, all expenses (including actual mortgage interest and the Section 24 credit), and your expected net profit after tax for both individual and company ownership. This is available at gov.uk/guidance/income-tax-on-property-income.
Review limited company mortgage options: Speak with a specialist buy-to-let mortgage broker who can provide up-to-date rates and criteria for both individual and limited company BTL mortgages, as rates vary considerably (typical BTL fixes vary by lender and product; always compare the latest rates).
Get Expert Coaching
Ready to take action on tax & accounting? Join Steven Potter's Property Freedom Framework for comprehensive, hands-on property investment coaching.