Most landlords researching this topic start by asking “which is cheaper, semi-commercial or full commercial?” That’s the wrong first question. The right first question is whether your property even qualifies as semi-commercial in the first place, because the answer determines which entire category of lender you’re allowed to approach and the two categories don’t compete on the same pricing at all.
The classification of semi-commercial
A semi-commercial property is a mixed-use building: a shop with a flat above it, a pub with a manager’s residence, an office with a maisonette attached. Most specialist lenders won’t call a property “semi-commercial” just because it has two uses. They apply a floor-space test. A common standard is that the residential portion must fall between 50% and 80% of total floor space. Drop below 50% residential and you’re in standard commercial mortgage territory. Push above 80% and some lenders will treat it as a residential or buy-to-let case with an ancillary commercial unit, which is a different product entirely.
This matters because landlords routinely assume their corner-shop-with-flat-above is automatically semi-commercial, approach a semi-commercial specialist, and get declined on a technicality before pricing is even discussed. Get the floor-space split confirmed, ideally with a measured survey, not a guess, before you start approaching lenders.
How the two products actually differ
A commercial mortgage finances a property used wholly for business purposes, whether that’s a warehouse, an office block, a care home, or a retail unit you let to a tenant business. The lender’s risk assessment rests entirely on the strength of the business covenant: how creditworthy is the tenant, how long is the lease, what happens to the property’s value if that tenant walks. This is why specialist trading assets such as pubs, hotels, petrol stations, care homes, sit at the expensive end of commercial lending: the property’s value is tied to a business operating from it, which makes the security harder to realise if things go wrong.
A semi-commercial mortgage finances a building that’s split between a commercial unit and a residential unit, and the lender has to underwrite two income streams with two different risk profiles simultaneously. That dual assessment is genuinely more complex underwriting, not just a marketing label, which is part of why fewer lenders offer it and why the ones who do charge for the complexity.
As of mid-2026, with the Bank of England base rate sitting at 3.75%, indicative pricing looks roughly like this: semi-commercial mortgage rates typically sit between 5.5% and 8% per annum depending on LTV, the commercial-to-residential split, property condition, and borrower profile. Standard commercial mortgages cover a wider band, most businesses see rates between 6% and 8.5%, though the strongest cases with 40% deposits and clean financials can access rates from around 5.5%. Specialist trading assets sit higher again, and owner-occupied deals generally beat investment deals on price across the board, because a business occupying its own premises is a cleaner risk than a landlord depending on a tenant who might leave.
Treat every figure above as a guide, not a quote. Lenders and brokers can only really give you a guide to pricing. You need to enquire directly or via your broker to know what any specific lender will actually offer, and your number will move based on your deposit, your experience as a landlord, and the specific property.
The income test that catches people out
Lenders don’t just check that your rental income covers the mortgage payment at today’s rate, they stress-test it against a much higher notional rate to make sure you’d survive if rates rose. Semi-commercial lenders commonly apply an interest cover ratio test using a notional stress rate of around 8% for variable products, which can sit well above the actual pay rate you’re being offered. The ICR threshold itself typically differs depending on how you’re buying: commonly 125% for limited company ownership versus a higher bar, often around 140–145%, for personal name ownership.
That gap between the pay rate and the stress rate is the reason a property that looks comfortably affordable on paper can still get declined, or get capped at a lower loan than you expected. It’s also why many semi-commercial deals end up constrained by income rather than by loan-to-value. The rent doesn’t stretch far enough under the stress test, even though the property itself would support a bigger loan against its valuation. If you’re buying through a limited company specifically to ease this constraint, that’s a legitimate strategy, but check the ICR threshold the lender is actually applying before you assume it’ll help your numbers and don’t assume the lower 125% figure applies everywhere.
A short or weak commercial lease is the other thing that quietly kills deals. A retail unit let on a rolling agreement or with eighteen months left on the lease reads as a risk flag to underwriters regardless of how reliable the actual tenant has been, because the lender is pricing the legal position, not your personal knowledge of the tenant.
Loan-to-value and what you’ll need upfront
Most commercial and semi-commercial lenders cap loan-to-value somewhere between 70% and 80%, with the stronger end of that range reserved for applicants with a solid balance sheet. That means you’re typically putting down 20–30% as a deposit, sometimes more for higher-risk property types. Bridging finance is sometimes used as a stepping stone and is useful if you’re buying a property that needs refurbishment, needs a change of use, or needs tenanting up before it qualifies for term debt, but bridging maximum LTV tends to sit lower, often in the mid-60% range, and the monthly cost accumulates fast if your exit (refinance, sale, or letting it up) takes longer than planned.
What this means practically
If you’re looking at a mixed-use building, get the floor-space split verified first, then talk to lenders who specifically do semi-commercial as not every commercial lender touches this category, and going to the wrong one wastes time and a credit search. If you’re looking at a wholly commercial asset, focus your due diligence on the tenant’s covenant strength and lease length, because that’s what’s actually being priced, more than the bricks and mortar. And whichever route you’re on, run your own numbers against an 8%-ish stress rate before you fall in love with a property, because that’s roughly what the lender will do regardless of what the headline rate looks like.
Use a broker with access to a wide panel rather than going direct to one lender. An specialist broker with access to a large panel of lenders will generally find better pricing than approaching a single lender and on a product this fragmented, where appetite and criteria vary significantly between lenders, that access matters more than it would on a vanilla residential mortgage.
Frequently Asked Questions
Is a shop with a flat above it automatically a semi-commercial mortgage?
No. Most lenders apply a floor-space test, commonly requiring the residential element to fall between 50% and 80% of total floor space. Below that range it’s treated as standard commercial; above it, some lenders push it toward residential or buy-to-let with an ancillary commercial unit. Get the split measured before approaching lenders, not estimated.
Can I get a normal residential or buy-to-let mortgage on a mixed-use building instead?
Generally no, not if the commercial element is a meaningful share of the building. Standard buy-to-let lenders underwrite residential tenancy risk only; they’re not set up to assess a commercial lease and business covenant alongside it. You’ll need a specialist semi-commercial or commercial lender.
Why is my mortgage being stress-tested at 8% when the actual rate I’m offered is 6%?
Lenders apply an interest cover ratio test against a notional stress rate, often around 8% for variable products, to confirm your rental income would still cover payments if rates rose. This is separate from your pay rate and is frequently the reason a loan gets capped lower than the property’s value would otherwise support.
Does buying through a limited company get me a better deal?
It can ease the income test specifically — limited company ICR thresholds are commonly lower (around 125%) than personal name thresholds (often 140–145%) — but check what a given lender is actually applying rather than assuming the lower figure applies by default. It also has separate tax and legal implications beyond mortgage pricing, which is a conversation for an accountant, not a mortgage broker.
Is bridging finance a good way into a semi-commercial property that isn’t fully let yet?
It can work as a stepping stone if the property needs refurbishment, a change of use, or time to find a commercial tenant before it qualifies for term debt. The trade-offs are a lower maximum LTV, often around the mid-60% range, and monthly interest costs that add up quickly. Don’t take a bridge without a dated, realistic exit plan already agreed.
How much deposit do I need?
Most lenders cap loan-to-value at 70–80%, so expect to put down 20–30% as a starting point, with weaker applicant profiles or higher-risk property types pushed toward the larger deposit end.
Is it worth using a broker rather than approaching a lender directly?
Usually yes on this type of lending specifically, because appetite and criteria vary significantly between lenders and not every commercial lender will even consider semi-commercial deals. A broker with a wide panel can save you from wasting a credit search on a lender who was never going to say yes.
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About the Author: Doug Hall, Director at 3mc
This article was written by Doug Hall, a Director at 3mc, one of the UK’s leading mortgage packagers, distributors and brokers. Doug has over 35 years of experience in the mortgage and specialist lending industry, giving him an unparalleled understanding of the challenges and opportunities facing landlords, brokers, and property investors across the UK. A recognised voice in the industry, Doug regularly speaks at major industry events and is widely respected by lenders, intermediaries, and fellow professionals alike. His insight is shaped by three decades on the front line of mortgage distribution, working closely with the brokers and lenders who keep the UK property market moving.