Let-to-buy is when you keep your current home and rent it out, rather than selling it, while taking out a new mortgage to buy the property you're moving into. It means you don't have to give up a home you've built equity in, and you may be able to generate rental income from it, but it does mean juggling two mortgages and taking on landlord responsibilities. This guide explains how let-to-buy works, what lenders typically look for, and the costs involved.
Key takeaway: Let-to-buy usually involves two separate mortgage applications happening at the same time: a buy-to-let mortgage or remortgage on your current home, and a residential mortgage on the new one. Most lenders want to see meaningful equity in your existing property before they'll consider it, and rental income needs to comfortably cover the buy-to-let repayment. A mortgage broker at Quanstrom Financial can run both applications alongside each other so nothing falls through the gap between them.
[[stats: 2 = Mortgages arranged side by side | 80% = Typical maximum loan to value on the let-to-buy side | Whole of = Market compared for both mortgages]]
What is let-to-buy?
Let-to-buy flips the usual buy-to-let process on its head. Instead of buying a new property specifically to rent out, you start with a home you already live in, and choose to rent it out instead of selling it when you move. In practice this normally means two things happen at once: your existing mortgage is replaced with a buy-to-let mortgage (or a specific let-to-buy product), freeing your current property up to be let, while you take out a separate residential mortgage to buy your new home.
It's a popular route for people who aren't ready to sell, perhaps because they want to hold onto a property in a good location, they're moving in with a partner and don't want to lose either property's equity, or they simply want to keep a foot on the property ladder as a landlord while moving on themselves.
Let to Buy calculator
Use the tool below to get a feel for how much equity your current home could release, and roughly what onward mortgage you'd be looking at. It's a starting point for the conversation, not a mortgage offer.
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How a let-to-buy mortgage works, step by step
A let-to-buy arrangement is usually structured as two connected but separate mortgages, often needing to complete around the same time. Tap any step below for more detail.
[[accordion: Step 1: Remortgage your current home onto a let-to-buy basis|Your existing residential mortgage is replaced with a buy-to-let mortgage, or a dedicated let-to-buy product where the lender is aware from the outset that a simultaneous residential purchase is happening. This releases your current home to be let out. ;; Step 2: Release equity to fund your deposit|If you can borrow more than your existing mortgage balance, the surplus is released to you as cash. This is what funds the deposit and buying costs on your onward purchase, and it can be topped up with your own savings if you want a larger deposit. ;; Step 3: Take a residential mortgage on your new home|At the same time, you'll need a standard residential mortgage to buy the property you're moving into, assessed in much the same way as any other home purchase, based on your income, outgoings and credit history. ;; Stamp duty: the 5% additional-property surcharge|Because you'd own two properties at the same time even temporarily, buying your new home usually means paying the standard stamp duty rates plus a 5 percentage point surcharge on the whole purchase price. ;; Completion: both mortgages usually complete together|Some lenders offer a dedicated let-to-buy product that only lends where there's a simultaneous residential purchase, often with the same solicitor acting on both transactions. Other lenders treat the two as separate, unconnected applications with their own timelines.]]
Good to know: Taking the most cost-effective route is important, so a mortgage broker at Quanstrom Financial will review whether you should add consent to let onto your current mortgage, or whether completing a let-to-buy will be better for you.
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Important things to consider
Beyond the basics, these are the details that tend to make the biggest difference to whether let-to-buy works for you, and what it will cost. Tap any to expand.
[[accordion: Let-to-buy or bridging?|If you want to secure an onward property before you've sold, but don't want to become a landlord, a bridging loan would likely be more suitable. A bridging loan comes with its own costs, but when weighed up against a let-to-buy mortgage, you may find the cost isn't too dissimilar. ;; Rental income must be sufficient to cover the mortgage required|Even if you have the equity available in your home, a lender must be satisfied that the new rent will cover your new mortgage payment, typically based on 125-145% of the mortgage payment at a notional rate of around 5.5%. Speak to a mortgage broker at Quanstrom Financial to check the achievable rental income on your current home would pass a lender's stress test. ;; Potential early repayment charges (ERCs)|Is your current mortgage on a fixed rate? Porting your current mortgage to a new home is sometimes possible, but it isn't always an option, and an early repayment charge may apply if you can't port. Speak to a mortgage broker at Quanstrom Financial to weigh up your options. ;; Will you sell your current property within 3 years?|You'll pay a 5% stamp duty surcharge on the new property, but this may be refunded by HMRC if the property you're keeping is sold within 3 years. You need to be able to cover this stamp duty upfront regardless, so it's important to understand the refund criteria before proceeding. ;; Can you borrow enough on the new property?|This is the key to everything: if you can't borrow enough on the new property, everything else is largely academic. Some lenders will factor in the new rental income even though it hasn't been received yet, while others will ignore the property being rented out altogether for affordability purposes. Speak to a mortgage broker at Quanstrom Financial to run a full borrowing assessment.]]
Let-to-buy: the key things to weigh up
Five things that tend to decide whether let-to-buy is the right route for you, and how the details affect what you can borrow. Tap any to expand.
[[accordion: Enough equity in your current home|Lenders typically want to see a meaningful amount of equity remaining once your property moves onto a buy-to-let basis, commonly landing around a maximum of 75-80% loan to value on the buy-to-let side, though this varies by lender. In other words, you'd usually need at least 20-25% equity in your existing home before it can be let out under a new mortgage. ;; The rent has to cover the borrowing|Buy-to-let lending, including the buy-to-let side of a let-to-buy arrangement, is typically assessed using rental cover rather than your personal income alone. Lenders usually want the expected rental income to reach a set percentage of the mortgage payment, often calculated using a notional stress rate to build in a buffer for future rate rises. Exactly how this is calculated varies significantly by lender and by your personal tax position. ;; Affordability on the new residential mortgage|You'll still need to be able to afford the residential mortgage on your new home on your income, in the same way as any other home purchase. Some lenders will let the buy-to-let side be treated as self-financing so it doesn't eat into this, others won't, which is worth checking before you commit to a particular lender. ;; Let-to-buy vs consent to let|Consent to let is a temporary permission from your existing residential lender, allowing you to rent your current home out on your existing residential terms, often used for a short period. Let-to-buy is a more permanent, structured move: your current home is remortgaged onto a proper buy-to-let basis from the outset, specifically so you can buy elsewhere and keep the original property as an ongoing rental investment. If you're planning to keep your current home as a rental for the long term, let-to-buy is generally the more suitable route. ;; The costs and responsibilities of two mortgages|Because you're arranging two mortgages rather than one, budget for two sets of arrangement, valuation and legal fees. Once your current home becomes a rental property, you'll also want to budget for landlord insurance, any letting agent fees, and ongoing maintenance, alongside gas and electrical safety checks, an EPC and deposit protection.]]
[[table: | Standard home move | Let-to-buy ;; Mortgages involved | One (on the new home) | Two (buy-to-let on the old home, residential on the new) ;; What happens to your current home | Sold | Kept and rented out ;; Stamp duty on the new home | Standard rates, or first-time buyer relief if eligible | Standard rates plus 5% surcharge (may be reclaimable if you later sell the old home within 3 years) ;; Ongoing costs | One mortgage payment, one set of household bills | Two mortgage payments, landlord costs on the rental, potential rental income ;; Best suited to | Buyers ready to give up their current property | Buyers who want to keep a foot in their current property as an investment]]
Real let-to-buy case studies
These are real, recently completed Quanstrom Financial cases. Client names have been changed to protect their privacy, but the figures, structures and outcomes are accurate. Tap any card to see the full case.
[[casestudy2: Partners buying together|Toby Quanstrom|June 2026|Sarah & Neil, Eastbourne|Sarah and Neil each owned their own property and wanted to buy a home together to live in, valued at £600,000. They liked the idea of keeping both existing properties rather than selling, and didn't want to be reliant on selling both before they could buy their new home.|We assessed Sarah and Neil's existing properties individually and raised £200,000 in total across both. This covered the £50,000 stamp duty bill on the new property, as well as a £150,000 (25%) deposit on the onward residential purchase. The new lender ignored both background properties, as they were self-financing.|Sarah and Neil completed on their own individual buy-to-let mortgages, and completed on their new family home on the same day. ;; Consent to let|Toby Quanstrom|January 2026|Jamie, Brighton|Jamie owns a flat in Brighton, two years into a five-year fixed rate, and was relocating for work to London, where he found a property for £550,000. His existing mortgage was already at 80% of the property's value, so raising further capital against it wasn't an option, though Jamie had £120,000 in inheritance he could put towards the new property.|Jamie's existing lender wasn't able to lend him enough to buy the new property, so to save Jamie from an early repayment charge on leaving his existing lender, we advised him to ask his lender for consent to let, allowing him to rent the flat out until the end of his fixed rate, with a view to remortgaging onto a buy-to-let in three years' time. As Jamie is a limited company director, we sourced a lender able to assess him on his company's net profits and director's salary.|Jamie secured consent to let on his existing property and completed on his new property in London. ;; Breaking the chain|Will Harrington|December 2025|Aaron, Heathfield|Aaron wasn't planning on moving, but his dream home came onto the market. Rather than list his own house and wait for a buyer, Aaron wanted to secure the property straight away.|We discussed Aaron's let-to-buy options, but since he wanted to sell his existing property as soon as possible, we established that let-to-buy wouldn't be suitable. Instead, we arranged bridging finance for Aaron, raising funds against both his current home and his new home to secure the purchase. The property cost £1.1 million, with a stamp duty liability of £108,750, which Aaron covered from savings.|Bridging finance was arranged and Aaron completed on his purchase. The sale of his original property completed in April, and the £55,000 stamp duty surcharge was refunded in full, as the sale fell within 3 years of the purchase.]]
Who is let-to-buy suited to?
Let-to-buy tends to suit people who aren't ready to give up a property they already own, whether that's because they want to hold onto it as a long-term investment, they've built up equity they don't want to lose by selling in a slow market, or they're combining households with a partner and want to keep both properties in play. It's less suited to anyone who needs to release all of their existing equity to afford their next home, since a let-to-buy arrangement is built around keeping a meaningful stake in the original property rather than cashing it in.
Frequently asked questions
Can I rent out my current home and buy another one?
Yes, this is exactly what a let-to-buy arrangement is designed for. It typically involves remortgaging your current home onto a buy-to-let basis while taking out a separate residential mortgage on the property you're moving into.
Do I need consent to let to buy another house?
Not necessarily. Consent to let is a temporary permission from your existing lender and is a different route to let-to-buy, which involves properly remortgaging your current home onto a buy-to-let product. Which is more suitable depends on whether you plan to rent your current home out long-term or just temporarily.
How much equity do I need for let-to-buy?
Lenders commonly expect a maximum of around 75-80% loan to value on the buy-to-let side of a let-to-buy arrangement, meaning you'd typically need at least 20-25% equity in your current home. This varies by lender.
What rental cover do lenders look for on a let-to-buy mortgage?
Many lenders want the rent achievable on your current home to reach around 125-145% of the mortgage payment, often calculated using a notional stress rate of around 5.5% rather than the actual pay rate, to build in a buffer for future rate rises. This varies by lender, so it's worth having a mortgage broker at Quanstrom Financial check your figures against current criteria.
Is a bridging loan a better option than let-to-buy?
It depends on whether you want to become a landlord. If you want to secure your onward property before selling but don't want to keep and rent out your current home, a bridging loan is likely to be more suitable. Bridging loans carry their own costs, which can end up not being too dissimilar to the costs of a let-to-buy arrangement, so it's worth comparing both.
Do I have to pay the stamp duty surcharge on a let-to-buy purchase?
Usually yes, since you'll temporarily or permanently own two properties. The standard rates plus a 5 percentage point surcharge normally apply to the new purchase, though you may be able to reclaim the surcharge if you sell your former home within 3 years.
Can both mortgages complete at the same time?
Often, yes. Some lenders offer dedicated let-to-buy products specifically designed for a simultaneous remortgage and purchase, sometimes requiring the same solicitor to act on both. Other lenders are happy to treat the two mortgages as unconnected applications with their own timelines.
Is let-to-buy the same as buy-to-let?
Not quite. Buy-to-let usually means buying a new property specifically to rent out. Let-to-buy is when you keep and rent out your existing home while buying a new one to live in yourself. The mortgage on the rental side works in a similar way to a standard buy-to-let mortgage in both cases.
What happens if I can't find a tenant straight away?
Void periods, where a rental property sits empty between tenants, are a real risk to plan for financially, since you'd still need to cover the buy-to-let mortgage payment even without rental income coming in. It's worth building this into your budgeting from the outset rather than assuming the property will be tenanted continuously.
Can I let-to-buy if I don't have much equity in my current home?
It can be more difficult. Since the buy-to-let side of the arrangement usually needs a meaningful amount of equity remaining, commonly 20-25%, a lack of equity may mean let-to-buy isn't available to you yet. A mortgage broker at Quanstrom Financial can talk through your options if this applies to you.
Will letting my home out affect my tax position?
Yes, rental income is taxable and there are specific rules around mortgage interest relief for landlords, which differ from how a residential mortgage is treated for tax purposes. This is a complex area, so it's worth speaking to a qualified accountant about your specific position alongside getting mortgage advice.
Related reading
If you're specifically looking at buying a second home to use yourself rather than renting your current one out, our guide to mortgaging a second home may be more relevant. If you're weighing up whether to sell and move in the usual way, take a look at our complete guide to moving home. And if stamp duty timing is a key part of your decision, our remortgage guide covers how switching lenders and timing works in more detail.
Written by Toby Quanstrom CeMAP, Director at Quanstrom Financial, a whole-of-market mortgage broker based in Eastbourne, East Sussex.
Your home may be repossessed if you do not keep up repayments on your mortgage. Some buy-to-let mortgages are not regulated by the Financial Conduct Authority.
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