For high-net-worth investors, buy-to-let property remains an attractive way to build wealth and generate income. However, assembling a portfolio of rental properties in 2025 is far more complex than owning a single buy-to-let. New tax policies, stricter lending criteria, and sweeping regulatory reforms have created a challenging landscape that demands careful planning and a strategic financing approach. It’s no longer enough to simply acquire properties and collect rent – portfolio landlords must actively manage risks and optimize their holdings to stay ahead.
Notably, many smaller landlords have been exiting the market under these pressures – recent data shows 15.6% of homes listed for sale in early 2025 were previously rentals, the highest rate in years (landlordstudio.com). Yet the rental sector itself is still running hot with demand outstripping supply (landlordstudio.com). This means property investment is not a dead end – it’s just changed. The landlords thriving in 2025 are those who adapt and take a more professional, long-term approach (landlordstudio.com). With the right strategy and expert team in place, HNW investors can continue to unlock significant opportunities and keep their portfolios performing at their best even in this evolving climate.
Even amid regulatory shifts, buy-to-let portfolios continue to hold strong appeal for HNW investors. Key reasons include:
Diversification: Owning multiple properties helps spread risk across different locations, tenant types, and property classes. By diversifying – for example, mixing prime London flats with high-yield regional houses – investors create a more resilient overall portfolio that isn’t overly reliant on one market.
Capital Growth: Prime property markets, particularly in London and major regional hubs, still offer robust long-term appreciation. Despite recent volatility, UK house prices are forecast to rise modestly (around 4% in 2025) as conditions stabilize (landlordvision.co.uk). HNW investors, who can afford to buy in well-located areas, count on equity growth over the years to significantly boost their net worth in addition to rental returns.
Stable Income Streams: Rental income provides steady cash flow that can service debt or be reinvested into further acquisitions. In fact, rents have hit record levels, average rents were up ~8.6% year-on-year at the start of 2025 (landlordstudio.com), which in turn pushed gross yields on newly purchased rentals to around 7.2%, a record high in recent history (mfsuk.com). Such healthy yields mean a well-managed portfolio can generate substantial ongoing income, often with 5–7%+ annual yields. This reliable cash flow is especially attractive to HNW individuals seeking an income-producing asset class to balance out equities or other investments.
Portfolio-Wide Performance: When applying for new loans, portfolio landlords should expect lenders to scrutinize the entire portfolio’s performance, not just the property being purchased or refinanced. This means demonstrating strong rental yields, minimal void periods, and prudent overall leverage across your holdings. Many lenders impose special criteria once you hit four or more properties – for example, they may require that the average loan-to-value (LTV) across the whole portfolio stay at or below ~75% (totallandlordinsurance.co.uk). They’ll also check that the total rental income comfortably covers all mortgage payments, often using stricter interest coverage ratios and stress tests than for single-property investors (totallandlordinsurance.co.uk). In practice, portfolio landlords need to keep an eye on their aggregate finances. Showing a well-managed, profitable portfolio can open doors to more competitive rates or higher borrowing facilities, whereas a poorly performing portfolio (e.g. several highly leveraged, low-yield properties) might limit your financing options.
Strategic Ownership Structure: Deciding how to hold your properties – in personal name, via a limited company, in a trust, or a partnership – is a critical upfront decision with major tax and financing implications. For example, buying through a limited company has become the structure of choice for many portfolio landlords: around 70–75% of new buy-to-let purchases now go into a company structure (buyassociationgroup.com). The reason is largely tax-driven. Properties in a company can still deduct mortgage interest as a business expense, whereas individual landlords can no longer deduct full interest (buyassociationgroup.com). Companies also benefit from tailored lending products, certain lenders and private banks offer bespoke portfolio loans exclusively to corporate entities. The bottom line: picking the right ownership structure from the outset, aligned with your long-term investment and succession plans, can save significant tax and interest costs over time. It’s advisable to consult with a tax adviser and our mortgage specialists early on, because restructuring later (transferring properties into a company or trust) can incur hefty stamp duty and tax charges.
A seismic change in landlord-tenant law is underway. The government’s Renters’ Rights Bill – expected to become law by 2025 – will abolish Section 21 “no fault” evictions (totallandlordinsurance.co.uk). In practice, this means landlords will no longer be able to evict tenants without providing a concrete reason. The traditional assured shorthold tenancy with a fixed end date will be replaced by open-ended periodic tenancies in almost all cases. If a landlord wants to regain possession, they must rely on specific allowable grounds (for instance, intending to sell the property or move in a close family member) and go through the Section 8 process, which involves proving the ground and often a court hearing.
Moreover, notice periods for evictions will be significantly longer. Landlords will generally have to give at least 4 months’ notice to tenants when seeking possession under the new rules. Tenants, by contrast, will be able to leave with just 2 months’ notice at any time. Rent increases will be limited to once per year, with a minimum two months’ notice, and renters gain the right to challenge above-market increases through a tribunal. Practices like rent bidding wars (where prospective tenants are asked to outbid each other) will be banned to keep rent hikes in check.
Sustainability and quality standards are rising fast on the agenda, bringing both compliance costs and potential opportunities for landlords. All indications are that in the near future, newly let properties will need an Energy Performance Certificate (EPC) rating of at least “C” – with target implementation by 2028 for new tenancies (landlordvision.co.uk). Portfolio investors must budget for upgrades such as better insulation, modern heating systems, double glazing, and possibly renewable energy installations to bring older properties up to standard. Doing this across a portfolio of properties can represent a significant capital outlay over the next few years.
Energy efficiency isn’t the only focus. The Decent Homes Standard – long applied in the social housing sector – is being extended to the private rented sector as well. This will impose minimum property condition requirements covering areas like adequate heating and hot water, modern wiring and plumbing, and reasonably updated kitchen and bathroom facilities. Landlords will be expected to ensure each property in their portfolio meets a baseline of decency and safety, or face penalties (totallandlordinsurance.co.uk). Additionally, the so-called “Awaab’s Law” is being rolled out to private rentals via the Renters’ Rights legislation (student-housing.co.ukstudent-housing.co.uk). This law will require landlords to address serious damp and mould issues within strict timeframes. Failing to promptly remedy hazards like mould will not only endanger your tenants’ health but could now lead to legal action and enforcement even in private rentals (student-housing.co.ukstudent-housing.co.uk).
Higher Transaction and Exit Taxes: The costs to both acquire and dispose of rental properties have gone up. In the October 2024 budget, the government increased the Stamp Duty Land Tax (SDLT) surcharge on additional properties from 3% to 5% (totallandlordinsurance.co.uk). This means that when you purchase a new buy-to-let or second home, you pay 5% extra stamp duty on top of standard rates. On the selling side, capital gains tax (CGT) on residential property sales has been adjusted: basic-rate taxpayers now pay 18% on gains, while higher-rate taxpayers face 24% CGT on property gains (totallandlordinsurance.co.uk). The result is that cashing out properties has become pricier, incentivising landlords to hold longer or find ways to offset gains.
Digital Tax Reporting and Possible New Taxes: The administrative burden of being a landlord is rising, especially for those with substantial rental incomes. The government’s Making Tax Digital (MTD) initiative for Income Tax is set to kick in from April 2026 for landlords earning above £50,000. This will require quarterly digital income and expense reporting, meaning filing 5 tax submissions a year instead of 1. HNW portfolio landlords will likely be among the first swept into this requirement. Ensuring you have good accounting systems or bookkeepers in place is crucial, as late or inaccurate filings could incur penalties. Beyond MTD, there’s growing talk of new taxes on rental income. In mid-2025, reports emerged that the Treasury was considering applying National Insurance contributions to landlords’ rental profits (theguardian.com). While as of now this is only a proposal, it reflects a broader political climate of targeting rental income as “unearned” income. HNW investors need to stay alert to these discussions, as any new tax could shift portfolio strategy.
Successfully navigating the current buy-to-let landscape requires more than just capital, it takes expertise and foresight. As specialist mortgage brokers, ONOZZI works closely with HNW clients to ensure their property portfolios are structured and financed optimally. We help investors:
Review and Restructure Portfolios: We conduct in-depth reviews of existing portfolios to identify refinancing opportunities or rebalancing strategies. This might mean refinancing high-interest loans to new products at better rates, unlocking equity from low-LTV properties to fund new purchases, or consolidating multiple mortgages into a more efficient facility. We also evaluate whether your portfolio’s current LTV mix and loan terms align with your goals, suggesting changes if needed to improve cash flow or reduce risk.
Access Bespoke Lending Products: HNW portfolio landlords often have needs that go beyond what the high-street banks can offer. We leverage our relationships with specialist lenders and private banks to secure bespoke financing solutions, such as portfolio loans that cover multiple properties, interest-only facilities with flexible terms, or offset mortgages that can integrate with your wider wealth management. Many of these products are not available directly to the public. Given that 2025 is expected to be a busy year for specialist lenders (mfsuk.com), having a broker to tap into this market is invaluable. We make sure our clients get competitive rates and terms tailored to their unique financial situation and investment strategy.
Coordinate Complex Transactions: Building and managing a property portfolio is a team effort. We frequently liaise with our clients’ solicitors, tax advisers, and surveyors, as well as the lenders’ underwriters, to streamline complex deals. Whether you’re incorporating a portfolio into a company, purchasing through a trust, or negotiating a multi-property package loan, ONOZZI oversees the moving parts so that financing doesn’t hold up your investment moves. Our goal is to save you time and hassle by project-managing the financing process from application to completion, ensuring all legal and compliance requirements are met along the way.
Above all, we act as a trusted partner in keeping your portfolio finance on the right track. Given the pace of regulatory and market changes, having expert guidance is more important than ever, portfolio lending criteria can be complex and vary widely by lender, so an experienced broker ensures you understand your options and get the best possible outcome.
Sources:
LandlordStudio – “Why Are Landlords Selling Up: A 2025 Wake-Up Call?” (June 2025) landlordstudio.comlandlordstudio.comlandlordstudio.comlandlordstudio.com
Landlord Insider (LandlordVision) – “2025 Rental Market Outlook: Insights for Landlords” (2024) landlordvision.co.uklandlordvision.co.uklandlordvision.co.uk
Total Landlord Insurance – “Key Dates for Landlords: What Does 2025 Have in Store?” (Nov 2024) totallandlordinsurance.co.uktotallandlordinsurance.co.uktotallandlordinsurance.co.uktotallandlordinsurance.co.uktotallandlordinsurance.co.uk
BuyAssociation – “Limited companies for buy-to-let have hit a record high in 2025” (Mar 2025) buyassociationgroup.combuyassociationgroup.combuyassociationgroup.com
MFS (Market Financial Solutions) – “Current State of the BTL Market & Outlook for 2025” (Report, 2024/25) mfsuk.commfsuk.com
The Guardian – “Treasury ‘considering taxing landlords’ rent’ to raise £2bn” (Aug 2025) theguardian.comtheguardian.comtheguardian.com
Student Housing Blog – “What Is Awaab’s Law? New Legal Requirements for Landlords in 2025” (June 2025) student-housing.co.ukstudent-housing.co.uk
Total Landlord Insurance – “Ultimate Guide to Being a Multi-Property Portfolio Landlord” (2024) totallandlordinsurance.co.uktotallandlordinsurance.co.uktotallandlordinsurance.co.uk
