Tax effects of letting out part of your home

by Aitch, posted in Capital Gains Tax

If you have tenants living in your property, it is important to understand the Capital Gains Tax (CGT) implications. In most cases, there is no CGT to pay when you sell a property that has been your main residence, as the gain is covered by Private Residence Relief (PRR). However, if you have let out part of your home, your entitlement to full PRR may be restricted.

However, you may be entitled to letting relief, provided you lived in the property at the same time as your tenant. Letting relief is only available where there has been shared occupation between homeowner and tenant.

The maximum letting relief available is the lower of £40,000, the amount of PRR due, or the gain attributable to the part of the property that was let. For example, if you rented out a large bedroom representing 10% of your home and later sold the property at a gain of £75,000, you would qualify for PRR on 90% of the gain (£67,500). The remaining £7,500 would relate to the let portion. As this is lower than both £40,000 and the PRR due, the full £7,500 would qualify for letting relief. In this scenario, the entire £75,000 gain would be covered by PRR and letting relief, meaning no CGT would be payable.

You are not considered to be letting out your home if you have a lodger who shares living space with you. Also, if children or parents live with you and contribute towards household expenses, this is not normally treated as a formal letting for CGT purposes, and full PRR is likely to remain available.

Source:HM Revenue & Customs | 23-02-2026
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Aitch
I'm Aitch, the Founder and CEO of CIGMA Accounting Ltd. As a Chartered Management Accountant and as a CIMA member, I've spent more than 16 years helping businesses, entrepreneurs, landlords, and individuals with tax planning, accounting, and HMRC compliance. As a chartered accountant in London, I'm passionate about making complex tax matters easier to understand and helping clients make confident financial decisions. Over the years, I've advised start-ups, SMEs, established companies, and high-net-worth individuals across a wide range of tax and accounting matters. My expertise includes Corporation Tax, Self-Assessment, Capital Gains Tax, Inheritance Tax planning, R&D tax relief, capital allowances, international tax, and resolving complex HMRC compliance issues. Whether clients need a business accountant, tax accountant, or strategic tax advisor, my focus is always on delivering practical advice that creates long-term value. One of my specialist areas is Making Tax Digital (MTD). I've worked extensively with businesses preparing HMRC's digital reporting requirements, helping them move to cloud accounting, improve financial processes, and adopt technology that makes compliance more efficient. I regularly speak at Making Tax Digital roadshows, industry events, and educational sessions in collaboration with Zoho Books, sharing practical insights into digital accounting, tax legislation, and the future of the profession. Many business owners looking for the best accounting firm in London are not simply searching for an accountant they're looking for trusted advice, responsive support, and long-term value. That's the approach I've taken in building CIGMA Accounting. My team and I work closely with businesses across London and the UK, providing accounting services, tax advisory, bookkeeping, payroll, VAT, company accounts, and strategic tax planning tailored to each client's goals. Through this website, I share practical guidance on UK taxation, Making Tax Digital, HMRC updates, Corporation Tax, Self-Assessment, and business finance. My aim is to provide reliable, straightforward information that helps business owners understand changing regulations, reduce compliance risks, and make informed financial decisions with confidence.
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