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Let to buy is where you keep the home you already live in, move its mortgage onto a buy to let basis, and take a residential mortgage on the new place you are moving into. It is two mortgages arranged at the same time, usually completing on the same day. Most people do not set out to do it. They end up doing it because the first property will not sell, or because two people are moving in together and neither wants to give up their home.
What is let to buy, and how is it different from buy to let?
Buy to let is buying a property specifically to rent out. Let to buy is letting a property you already live in so you can go and buy another one. The words are almost the same and the situations are not.
The difference matters for a practical reason. In a let to buy, the property you are letting is your own former home, which means the case often sits inside consumer buy to let rather than standard investment buy to let. That changes which lenders will look at it.
Why do people end up doing it rather than choosing it?
Three situations come up again and again. A couple moving in together where both already own. Someone who has found the next house before the current one sold. And someone who does not want to sell in a soft market and would rather let the property and wait. In all three the property is being let because of circumstances, not because anyone drew up an investment plan.
Let to buy is two mortgages arranged together, a buy to let on the home you are leaving and a residential on the one you are moving to.
Equity raised on your current home usually becomes the deposit on the new one.
The higher rate of stamp duty applies to the new purchase, currently an extra 5%.
The stamp duty refund generally does not apply, because you are keeping the old home rather than selling it.
Letting a home you lived in often falls inside consumer buy to let, which narrows the lender list.
How do the two mortgages work together?
They are separate applications, often with different lenders, and they usually need to complete together. The buy to let mortgage on your existing home releases the deposit for the new purchase, and the residential mortgage on the new property completes on the same day. That is why let to buy has a reputation for being fiddly. It is not that either mortgage is unusual on its own, it is that the timing has to line up.
An important consequence: the residential lender on the new property will take the buy to let mortgage into account when working out what you can afford. Some lenders will disregard the buy to let entirely if the rent covers it comfortably. Others will not. That difference alone can decide which lender you can use.
Can you use equity from your current home as the deposit on the next one?
Usually yes, and that is normally the whole point of doing it. You raise money against your existing home when you move it onto a buy to let mortgage, and that money becomes the deposit on the new one. How much you can raise depends on the value of the property and, crucially, on whether the rent will cover the new, larger loan at the lender’s stress rate. There is a fuller explanation of how that test works in my guide to how a buy to let remortgage works.
What stamp duty applies when you keep the first property?
Because you are buying a second property while keeping the first, the higher rate for additional dwellings applies to the new purchase. That is currently an extra 5% on top of the standard rates, and on a normal family home it is a serious number. It is payable on the purchase, not on the property you are letting.
Can you get that extra stamp duty back later?
Usually not in a genuine let to buy, and this is the part that is most often explained wrongly. The refund exists for people who buy a new main residence before selling the old one, and it applies where the previous main residence is sold within 36 months. In a let to buy you are deliberately not selling the previous main residence. You are letting it. So the surcharge is generally a cost you pay and keep, not a temporary cash flow issue you reclaim.
Several well-known guides gloss over that distinction and leave people expecting money back that is not coming. Where the 36 month window does matter is if your plans change. If you later decide to sell the old home inside that window, the refund may come back into play, so it is worth diarising the date rather than forgetting it. Stamp duty is a tax question and your solicitor or accountant should confirm your own position before you commit.
Speak to an expert
Thinking about keeping your home and buying another? Call me on 01425 203055 or email info@htgmortgages.com. I will tell you early if the numbers do not work.
What will a lender want to see on the property you are letting?
Chiefly the rent. Buy to let borrowing is driven by a rental cover test rather than by your salary alone, so the lender wants a surveyor’s view of what the property would let for, and the rent has to exceed the mortgage interest at a stressed rate by a set margin. If your existing home is a nice house in an expensive area, that test is often harder than people expect, because desirable areas tend to have lower rental yields.
Is your let to buy mortgage a consumer buy to let?
Frequently, yes. Letting a home you have been living in is the classic example. It is not decided by which you would prefer and it is not settled by signing a business declaration, it is decided by the substance of what you are doing. Worth establishing early, because it narrows the lender list.
What tends to go wrong with the timing?
Two things. The first is the two completions drifting apart, usually because one lender is slower than the other, which leaves you either owning two properties with the wrong mortgages on them or unable to complete at all. The second is starting too late. Two applications with two lenders and one solicitor coordinating both takes longer than a single purchase, so the time to start the conversation is before you offer on the new place, not after.
Where to get this looked at
Let to buy is one of the more common reasons people ring me, and the useful part is usually the first half hour, working out whether the rent on your current home will support the money you need to pull out of it. If it will not, better to know that before you offer on anything. Related reading: can I rent out my house on a residential mortgage, the buy to let remortgage page, and the buy to let hub. My fee is a flat £350, payable only once your mortgage offer is issued, and here is how that compares with percentage broker fees. Information correct as at August 2026. This is general information rather than advice on your own situation, and tax questions belong with your accountant or solicitor.
The other half of most let to buy plans is switching the old mortgage across, which I walk through in can I change my mortgage to a buy to let.
Related reading: can you have two mortgages, getting a mortgage on a second home and remortgaging to buy another property.
Need Personal Mortgage Advice?
Every buyer’s situation is different. While this guide explains the general rules, the right mortgage for you depends on your income, deposit, credit history and future plans. If you’d like tailored advice, I’m here to help, with whole-of-market coverage.
