Buy to Let Business Loans

Setting the scene for buy to let finance

Buy to let has shifted from a side investment into a proper business for many UK owners, particularly as rates, tax rules and lender criteria have evolved. The right funding can help you purchase, refinance or consolidate a portfolio, but it also introduces obligations that behave more like business borrowing than a standard residential mortgage. That means lenders will look closely at rental coverage, property type, your experience and how the borrowing is structured.

Market conditions matter too. Recent UK lending data shows strong activity, with tens of thousands of new buy to let loans written in a single quarter and average rental yields sitting in the low to mid single digits, while average new loan pricing has been around the high 4% range. At the sharper end, limited company buy to let headline rates have been advertised from 3.98% at 75% loan to value, although fees and underwriting still determine your true cost.

Understanding the rate is only half the job. Understanding the total cost and the lender’s tests is what protects your margin.

Is this relevant to you?

This is for UK business owners and landlords who treat property as an income-generating enterprise, whether you own one rental through a company, run a small portfolio, or are planning to scale. It is also useful if you are considering moving from personal ownership to a limited company structure, or if you need to refinance to improve cash flow. If your property is mixed-use, multi-unit, or sits outside standard residential criteria, the commercial angle becomes even more important.

What people mean by a buy to let business loan

A buy to let business loan is funding used to purchase or refinance a rental property (or portfolio) where the primary repayment source is rental income. In practice, this often takes one of two forms: a limited company buy to let mortgage for residential investment property held in a company, or a commercial buy to let facility for properties that fall into commercial or semi-commercial categories.

For limited company buy to let, pricing can be competitive, especially at lower loan to value ratios. Some products in the UK market have shown headline rates starting from 3.98% at 75% LTV for purchases and remortgages, with fees such as booking, arrangement, deeds and administration potentially applying. For commercial buy to let, lenders typically price higher than standard residential buy to let due to perceived risk, and they tend to apply tighter underwriting around lease quality, property type and exit strategy.

How the funding typically works in practice

Lenders generally assess three things: the asset, the rent, and the borrower. The property must fit criteria (construction, location, condition and intended use), and the rent must cover the mortgage payment by a set margin. In the UK, it is common to see rental stress tests and interest cover ratios, and recent lending data has shown interest cover ratios improving to above 200% on average for new buy to let lending, reflecting stronger coverage.

Deposit and loan to value are central. For commercial buy to let, it is common to need a 25-35% deposit, equating to around 65-75% LTV, and the rent may need to cover roughly 125-145% of payments depending on the lender and product. Loan terms can vary widely, with some lenders offering 5-25 year terms, and repayment options may include interest-only, capital repayment, or a mix, depending on the case.

Why structure and timing can change the outcome

The structure you choose affects both affordability and tax. Many landlords favour limited company ownership because mortgage interest and certain running costs can be deducted from rental income before corporation tax, whereas individual landlords have faced restrictions on mortgage interest relief since 2017. That can materially change your post-tax position, although company ownership also brings added administration and may affect how profits are extracted.

Timing matters because rates and lender appetite shift. UK buy to let data has recently shown average new loan rates around 4.77% in late 2025, alongside healthy average gross rental yields around 7.18% and strong year-on-year growth in new lending volumes. For business owners, this highlights a key point: the best time to refinance is often when your portfolio is stable and your documents are in order, not when a deadline is looming.

Pros and cons at a glance

Common pitfalls that can cost you money

The biggest trap is focusing on the interest rate while ignoring fees and stress testing. A product with a low headline rate can still be expensive if the arrangement fee is calculated as a percentage of the loan, or if you need to refinance again sooner than expected. Equally, rental calculations can catch borrowers out, especially if the lender uses a stressed rate that is above the pay rate.

Property type is another pressure point. Flats above shops, ex-local authority stock, multi-unit blocks and mixed-use assets can all be lendable, but not every lender will treat them the same way. For commercial buy to let, expect scrutiny of tenancy quality and lease terms, and plan for higher deposit requirements. Finally, do not underestimate the importance of clean, consistent documentation: bank statements, accounts (where relevant), and a clear picture of portfolio performance can materially improve lender confidence.

Alternatives worth considering

1. Remortgage to a new fixed rate product to improve payment certainty.

2. Portfolio refinance to consolidate multiple loans and simplify cash flow.

3. Bridging finance for time-sensitive purchases, with a clear refinance exit.

4. Second charge lending against existing property equity (where suitable).

5. Unsecured business lending for smaller needs where property security is not required.

FAQs business owners ask

What deposit do I need for a commercial buy to let?

Many commercial buy to let lenders look for around 25-35% deposit, commonly lending at roughly 65-75% LTV, subject to the asset and rent.

Are limited company buy to let rates lower than commercial buy to let?

Often, yes. Limited company residential buy to let can be priced more keenly, while commercial buy to let is frequently 1-2% higher due to risk and property characteristics. Your final rate depends on LTV, rent, experience and property type.

Can a limited company deduct mortgage interest from rental income?

In many cases, yes. Limited companies can generally deduct mortgage interest and allowable running costs from rental income before corporation tax, which is a key reason company structures are popular.

How do lenders check affordability for buy to let borrowing?

They typically stress test rental income against mortgage payments using an interest cover ratio approach. Some lenders may also consider personal income, especially where the property is non-standard or the rent is tight.

Can I finance a larger portfolio through one lender?

Potentially. Some UK lenders support portfolio borrowing into the multi-million range, but expect more detailed underwriting, including portfolio schedules, property performance and experience.

Where Kandoo fits in

Kandoo is a UK-based commercial finance broker. We help business owners and landlords navigate lender criteria, compare realistic total costs (not just headline rates), and identify options aligned with your portfolio and timeline. Where your case involves limited company ownership, non-standard property, or a more commercial profile, Kandoo can connect you with suitable lenders and help you prepare the information they are most likely to request.

Disclaimer

This article is for general information only and does not constitute financial, tax or legal advice. Rates, fees and criteria can change, and eligibility depends on your circumstances and the property. You should consider professional advice before acting.