What about a flat above a shop?
That is semi-commercial, sometimes called mixed use, and it has its own lenders and its own article. A semi-commercial property is one title with both commercial and residential parts, the classic being a shop with a flat above. Some lenders treat it as commercial, some have a specific mixed-use product, and how much of the building is residential affects which ones will look at it.
A mixed-use mortgage can be regulated where at least 40% of the property, measured across the floor areas of each storey, is used or intended to be used as a home. In practice that matters where you or a close family member (a spouse or partner, parent, child, sibling, grandparent or grandchild) live there: where the residential part is let to a tenant, the loan is usually an investment property loan, which sits outside the regulated regime for a separate reason. Borrowing through a limited company sits outside it too, because the test applies to credit provided to an individual or to trustees. It turns on the specific building, who is borrowing, and who lives there, so ask us.
Our article on semi-commercial mortgages for a shop with a flat above covers what lenders look at in detail.
Can I convert a commercial building into flats and let them?
Yes, though the finance usually comes in two stages, because a buy-to-let lender lends on homes and the building is not one yet. The first stage funds the purchase and the conversion, typically with bridging or development finance. The second stage, once the flats are finished and lettable, is a buy-to-let mortgage that repays the first loan, often at the improved value.
The second stage is where plans meet the buy-to-let tests. Each flat has to be a property a buy-to-let lender will lend on, and the rent has to support the mortgage. Many lenders on our panel look for rental cover of 125%–145% of the mortgage payment (125% for a limited company or a basic-rate taxpayer, 145% for a higher- or additional-rate taxpayer), worked out at a stress rate of around 5.5% (indicative, checked September 2026, not the terms of any one lender, and not a recommendation). What you're offered depends on your circumstances.
Agreeing the buy-to-let exit before you start is the idea behind bridge-to-let, which our article on bridge-to-let and standard bridging loans explains. Whether a building can be converted, and on what terms, is a planning and legal question: speak to a solicitor, and a planning consultant where one is needed, before you commit to a purchase on that basis.
Is a commercial investment mortgage regulated?
No. Commercial mortgages for business or investment purposes are not regulated by the Financial Conduct Authority. The reason is the building, not the purpose of the loan: a shop, office or warehouse is not used as a home, so it falls outside the regulated regime. That means the protections and remedies attached to a regulated contract do not come with the loan.
Is a buy-to-let mortgage regulated?
Most buy-to-let mortgages are not regulated by the Financial Conduct Authority. Consumer buy-to-let — broadly, letting a property you did not buy as an investment, such as one you inherited or used to live in — is the exception and is regulated. If you're unsure which applies to you, ask us.
Can I buy a commercial or mixed-use property through a limited company?
Often, yes, depending on the lender. Whether it suits you is a tax question as much as a mortgage one, so speak to an accountant before deciding how to hold the property. Our article on limited company buy-to-let explains how lenders approach company borrowers.
What does your advice cost?
Our standard fee is £495, payable when your application is submitted. In some more complex cases, an additional broker fee of up to 1% of the loan may apply. The first conversation is always free, and we always confirm your total fee in writing before any work starts.
We are also paid a procuration fee by the lender if your case completes, and we will tell you what it is before you proceed.
The short version
A buy-to-let mortgage is for a home let to tenants. A building let to a business takes a commercial investment mortgage, where the lease and the tenant matter as much as the rent.
A flat above a shop is semi-commercial, with its own lenders, and whether that loan is regulated turns on who lives there.
Converting a commercial building into flats usually means a bridge or development loan first, then a buy-to-let mortgage once the flats are lettable.
Commercial mortgages for business or investment purposes are not regulated by the Financial Conduct Authority.
Read next: our commercial mortgage page, our buy-to-let mortgage page, or our commercial property guide.
Lawes Financial Limited (FRN 1046161) is an appointed representative of Andrew Charles Consulting Ltd, which is authorised and regulated by the Financial Conduct Authority (FRN 304904).
