Considering putting my BTLs into a limited company to avoid Section 24. What are the pros and cons I really need to consider for an existing portfolio? Is it worth the hassle and extra costs?
Quick Answer
Transferring an existing BTL portfolio into a limited company can offer tax efficiency by allowing full mortgage interest deduction, but it triggers substantial upfront costs like SDLT, CGT, and increased legal/mortgage fees, which must be carefully evaluated against long-term benefits.
## Tax Efficiency Benefits of Limited Company Buy-to-Let Ownership
Transitioning an existing buy-to-let (BTL) portfolio into a limited company structure, often referred to as 'incorporation', can provide several tax advantages for property investors by allowing full mortgage interest relief. Since April 2020, individual landlords cannot deduct mortgage interest from rental income to reduce their income tax liability, instead receiving a 20% tax credit. For higher and additional rate taxpayers, this means a significant portion of their profits are taxed before finance costs are effectively accounted for. A limited company, however, is subject to Corporation Tax, which currently stands at 25% for profits over £250,000, and a small profits rate of 19% for profits under £50,000.
**Tax Savings on Mortgage Interest:** Within a limited company, mortgage interest and other finance costs are treated as legitimate business expenses, deductible from rental income before Corporation Tax is calculated. For a landlord with a property generating £1,000 per month in rent and £400 per month in mortgage interest, an individual setup means £1,000 is taxed, with only a 20% mortgage interest tax credit applied later. In a company, the £400 interest is deducted, meaning only £600 is subject to Corporation Tax. This can significantly improve net profitability, particularly for those in higher income tax brackets.
**Income Extraction Flexibility:** As an individual, all rental profits are part of your personal income. Within a limited company, profits accumulate within the company, subject to Corporation Tax. Funds can then be extracted strategically through dividends, salaries, or pension contributions, potentially offering greater tax efficiency depending on other income sources and personal tax allowances. For example, dividends can benefit from a tax-free allowance and are taxed at lower rates than income tax, though these rates vary (e.g., 8.75% for basic rate, 33.75% for higher rate in the 2025/26 tax year).
**Estate Planning Opportunities:** Limited company structures can also offer advantages for long-term wealth transfer and inheritance tax planning. Shares in a company are generally easier to transfer than direct property ownership, and certain business property reliefs may apply, although the specifics depend on whether the company is considered a 'trading' company, which is often not the case for purely BTL holding companies. This complex area requires specialist advice to ensure compliance and maximise benefits.
## Significant Costs and Hurdles of Incorporating an Existing Portfolio
While the tax benefits of a limited company structure are appealing, especially in the wake of Section 24, transferring an existing portfolio is not without considerable expense and complexity. The process involves legally selling the properties from your personal name to your newly formed limited company, triggering several taxes and fees.
**Stamp Duty Land Tax (SDLT):** This is often the largest single cost. When properties are transferred, the limited company is treated as a separate legal entity buying the properties. This means SDLT is payable on the market value of the properties being transferred. Crucially, the additional dwelling surcharge of 5% (increased from 3% in April 2025) will almost always apply, as the company will typically own more than one property. For example, transferring a £250,000 property incurs 5% on £250,000 which is £12,500. A portfolio of four properties each valued at £250,000 would incur SDLT costs of £50,000. Reliefs like Multiple Dwellings Relief (MDR) have been abolished as of June 2024, meaning each property is now assessed individually for SDLT purposes. There is a potential exception for 'incorporation relief' under certain conditions (e.g., if you are transferring an existing property business with at least 20 hours a week of active management), but this is extremely rare for typical BTL landlords and requires stringent criteria to be met, meaning most landlords will face the full SDLT charge.
**Capital Gains Tax (CGT):** When you sell a property from your personal name to your limited company, it is treated as a disposal for CGT purposes. This means you will be liable for CGT on any capital gain – the difference between your purchase price (plus allowable costs) and the current market value. Basic rate taxpayers pay 18% CGT on residential property gains, while higher and additional rate taxpayers pay 24%. The annual exempt amount is £3,000. Transferring an existing portfolio built up over years can trigger substantial CGT liabilities, potentially outweighing the Section 24 benefits for many years. For instance, if a property purchased for £150,000 is now worth £250,000, the £100,000 gain would be subject to 24% CGT for higher rate taxpayers, equating to £24,000, minus the annual exempt amount.
**Mortgage Costs and Availability:** Existing residential mortgages or standard buy-to-let mortgages are typically not transferable to a limited company. The limited company will need to apply for new BTL mortgages, which are specifically designed for companies. Lender products for limited companies often come with higher interest rates (e.g., 0.25-0.5% higher than individual BTL rates) and higher arrangement fees (e.g., 1-2% of the loan amount). Given the Bank of England base rate at 4.75% as of December 2025, typical BTL rates are 5.0-6.5%, so company rates could be 5.25-7.0%. There are also fees for valuations, legal work, and mortgage broker services associated with securing finance for each property within the new company structure. This re-mortgaging process for an entire portfolio can be time-consuming and costly, often requiring bespoke legal and financial advice to navigate.
**Administrative Burden and Accounting Costs:** Operating a limited company involves increased administrative obligations compared to being a sole trader landlord. This includes filing annual accounts with Companies House, submitting Corporation Tax returns to HMRC, maintaining statutory registers, and ensuring compliance with company law. The accounting fees for a limited company are considerably higher than for a sole trader, typically ranging from £800 to several thousand pounds per year, depending on the portfolio size and complexity. This ongoing cost must be factored into the long-term profitability calculations, impacting the overall `landlord profit margins` from month to month.
## Investor Rule of Thumb
The decision to incorporate an existing BTL portfolio revolves around a detailed calculation of the upfront costs (SDLT, CGT, mortgage fees) versus the projected long-term tax savings on mortgage interest and the flexibility of income extraction capabilities within your specific tax situation.
## What This Means For You
Most landlords do not lose money by exploring options like incorporation; they lose money by making significant financial decisions without forensic analysis. If you are sitting on a substantial equity gain and considering the incorporation of an existing portfolio, the calculations for SDLT and CGT alone can be prohibitive. These are exactly the complex financial models we dissect at Property Legacy Education, helping you understand the real `ROI on rental property` under various scenarios. We guide you through assessing the `BTL investment returns` against the full cost of incorporation, ensuring you make an informed decision tailored to your portfolio and personal circumstances, preventing costly errors or missed opportunities for `rental yield calculations` improvement.
Steven's Take
The allure of mitigating Section 24 by moving an existing BTL portfolio into a limited company is strong for many UK landlords, particularly higher-rate taxpayers. However, the costs associated with this transition are often underestimated and can nullify the purported benefits for years, if not decades. The primary hurdles are SDLT and CGT. For example, on a portfolio of properties with substantial capital appreciation, the immediate CGT liability, coupled with the 5% SDLT surcharge on current market value, can be astronomical. I've seen landlords incur six-figure upfront bills with this strategy, meaning the years of Corporation Tax savings might only just cover these initial costs. It’s absolutely critical to conduct a detailed, property-by-property financial model that projects these costs against future tax savings, factoring in increased mortgage rates for limited company products and higher accounting fees. For every £1 saved from Section 24, you need to know how much you're spending to achieve that saving today.
What You Can Do Next
Step 1: Consult a specialist property tax accountant - Search 'property tax accountant' on ICAEW.com or ATT.org.uk. They can model the exact SDLT and CGT implications for your specific portfolio, considering any potential reliefs, and provide a clear projection of the upfront costs and long-term tax savings.
Step 2: Obtain formal mortgage advice from a limited company BTL broker - Use resources like the Specialist Finance Centre or NACFB (National Association of Commercial Finance Brokers) to find a broker. They can provide illustrations for new limited company mortgage rates and associated fees, which are typically higher than individual BTL products, ensuring your financial projections are accurate.
Step 3: Review your existing property valuations and purchase costs - Gather all documents related to the purchase price, legal fees, and any capital improvements for each property. This data is essential for your property tax accountant to accurately calculate potential Capital Gains Tax liabilities upon transfer.
Step 4: Analyse your current rental income and mortgage interest expenditure - Create a detailed spreadsheet for each property, outlining rental income, current mortgage payments, and other operating costs. This helps quantify the actual impact of Section 24 and the potential Corporation Tax savings within a limited company structure.
Step 5: Understand administrative and compliance costs - Contact several property-specialist accountancy firms for quotes on annual limited company accounting and compliance services. This provides a realistic figure for ongoing administrative overhead, a key factor often overlooked in initial calculations.
Step 6: Calculate a break-even point - Work with your financial and tax advisors to determine how many years it would take for the projected tax savings to offset the upfront SDLT, CGT, and re-mortgaging costs, alongside increased ongoing administrative expenses. This crucial metric will inform if the strategy makes financial sense for your specific investment horizon.
Get Expert Coaching
Ready to take action on tax & accounting? Join Steven Potter's Property Freedom Framework for comprehensive, hands-on property investment coaching.