Limited Company Buy-to-Let Mortgages: A 2026 Guide for Landlords and Portfolio Investors

More new buy-to-let purchases are now made through limited companies than in personal names, a shift that’s been building steadily since the tax rules for individual landlords changed in 2017. If you’re weighing up whether to buy your next property, or restructure an existing one, through a company, here’s what actually matters for the mortgage side of the decision.

Why this became the default route for so many landlords

Since April 2020, individual landlords have not been able to deduct mortgage interest as a business expense against rental income. Instead, they receive a 20% basic-rate tax credit on finance costs, regardless of their actual marginal tax rate. For a higher-rate taxpayer paying 40% income tax, the effective tax cost on the same rental profit is roughly double what a company would pay under corporation tax, which sits at 19% for profits under £50,000 and 25% above £250,000, with a tapered rate in between.

That single change, often referred to as the Section 24 restriction, is why incorporation moved from a niche strategy to the mainstream approach for many landlords, particularly higher-rate taxpayers and those building a portfolio rather than holding one property.

It isn’t automatically the right answer for everyone, though. A basic-rate taxpayer already receives the same 20% tax credit that a company effectively mirrors through its lower tax rate, so the advantage is far less pronounced, and the ongoing costs of running a company, accountancy fees, confirmation statements, dividend tax on any profit you extract, can outweigh the benefit for a single, lightly-mortgaged property.

How limited company buy-to-let mortgages actually work

Most lenders require the property to be held in a Special Purpose Vehicle (SPV), a company set up solely to buy, hold, and manage investment property, rather than a trading company with other business activities. Lenders prefer SPVs because the accounts are simple and the purpose is unambiguous, which makes underwriting considerably more straightforward.

A few things to know before you set one up or approach a lender:

• SIC codes matter. Most lenders want to see a Standard Industrial Classification code linked to property investment, commonly 68100 (buying and selling of own real estate) or 68209 (other letting and operating of own or leased real estate).
• Personal guarantees are standard. The company is the borrower on paper, but directors are almost always required to give personal guarantees. You remain personally liable if the company can’t service the debt, which means the limited liability structure doesn’t remove your personal exposure to the mortgage itself.
• Director and shareholder limits. Many lenders cap the number of directors or shareholders at four, and some require the company to have been actively trading rather than a newly formed shelf company, though this varies by lender.
• Interest coverage ratios are often more favourable. Lenders frequently apply a lower stress-test threshold to company applications, sometimes around 125%, compared with 140% to 145% commonly applied to individual higher-rate taxpayers. On the same property, that can translate into meaningfully more available borrowing through a company structure.

The rate difference has narrowed, but hasn’t disappeared

Limited company buy-to-let rates used to carry a noticeably higher premium over personal-name lending. That gap has closed significantly, and on some products the pricing is now identical. Where a premium still exists, it typically sits in the region of 0.1 to 0.3 percentage points, though this moves with the wider rate environment and varies by lender.

Whether that premium is worth paying comes down to your tax position: how much of your rental profit you’re extracting immediately versus retaining in the company, and your personal marginal tax rate. This is a calculation best run jointly with your accountant rather than decided on the mortgage rate alone, because the tax outcome usually outweighs a small difference in interest rate over the medium term.

Transferring existing properties into a company

If you already own buy-to-let property personally and are considering moving it into a company, be aware this is treated as a sale by you to the company for tax purposes, not a simple change of paperwork. That typically means:

• Capital Gains Tax may be due on any gain in the property’s value since you bought it.
• Stamp Duty Land Tax is payable by the company on the transfer, as if it were a normal purchase, plus the additional property surcharge.
• Two sets of legal costs, since you need conveyancing on both the “sale” from you and the “purchase” by the company, along with your existing lender’s consent to redeem the mortgage.

For a smaller portfolio of two to four properties, the combined cost of incorporating an existing holding often takes a decade or more to recoup through the ongoing tax saving, so this decision is far more clear-cut for new purchases than it is for transferring what you already own. Highly leveraged portfolios held by higher-rate taxpayers tend to see a shorter payback period, but it’s a calculation, not a rule of thumb, and it should be run with your accountant before you commit.

Portfolio landlords: a different underwriting conversation

If you hold, or are building towards, four or more mortgaged buy-to-let properties, most lenders classify you as a portfolio landlord and assess your application differently. Rather than looking at the single property in isolation, they’ll want to understand your entire portfolio: total borrowing, overall loan-to-value across all properties, rental coverage on the portfolio as a whole, and your experience managing multiple tenancies.

This is where a limited company structure often makes practical sense beyond the tax position. It centralises reporting, simplifies future applications because the lender is assessing a company with a track record and clean accounts rather than reassembling an individual’s finances each time, and gives you a structure that can bring in family members or co-investors more cleanly than shared personal ownership.

Questions worth asking before you decide

• Is your marginal tax rate high enough that the corporation tax treatment meaningfully beats the personal 20% finance cost credit?
• Are you planning to reinvest profit into further purchases, or extract most of it as income each year?
• Is this a new purchase, where incorporation is usually the simpler decision, or an existing property, where transfer costs need to be weighed against the ongoing saving?
• How many properties are you planning to hold within three to five years? Portfolio-level lending criteria start to matter well before you reach double digits.

None of these questions have a single right answer that applies to every landlord, which is exactly why this decision benefits from advice rather than a rule of thumb picked up from a forum.

How we help

We work with individual landlords, portfolio investors, and clients incorporating for the first time across Berkshire, Buckinghamshire, and the wider Thames Valley. Because we’re whole-of-market, we compare personal-name and limited company products side by side, and we work alongside your accountant where the tax position needs a joined-up view rather than a mortgage-only answer.

Book a free consultation to talk through whether a limited company structure fits your plans, whether you’re buying your first buy-to-let or restructuring a growing portfolio.

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Related guides

• Buy-to-let mortgage advice
• HMO mortgages: 2026 UK landlord’s guide
• Buy-to-let mortgages in Berkshire & Buckinghamshire
• Stamp Duty calculator

Buy-to-let mortgages, including limited company and SPV mortgages, are not regulated by the Financial Conduct Authority in most circumstances. This article is for general information only and does not constitute financial, legal, or tax advice. Tax treatment depends on individual circumstances and may change in future; speak to a qualified accountant before making a decision.