A Let to Buy mortgage guide in 2026 describes a structured way for homeowners to move property while retaining their current home as a rental asset. It is typically used when a borrower wants to purchase a new main residence but does not want to sell the existing property immediately. The arrangement involves two linked mortgage applications assessed together by a lender or separate lenders, depending on affordability and policy. What is a Let to Buy mortgage? It is a financial solution where an existing residential property is converted into a rental property, while a new residential mortgage is taken out for a different home. The original mortgage is switched to a buy-to-let product, and the new property is financed as a primary residence https://smartcitymortgages.co.uk/blog/let-to-buy-mortgage-guide-how-it-works-criteria-costs-and-risks-2026/ . This structure allows a transition between homes without forcing a sale in a potentially unfavorable market. How does a Let to Buy mortgage work? The lender evaluates whether the existing property can generate sufficient rental income to support the buy-to-let mortgage. At the same time, affordability checks are completed for the new residential mortgage based on income, expenses, and credit profile. In many cases, the process is coordinated so both mortgages complete simultaneously to reduce risk exposure. Who is Let to Buy suitable for? It is generally suitable for homeowners who need to move but prefer to retain their current property as a long-term investment. It may also appeal to individuals relocating for work, families upgrading homes, or borrowers who believe their existing property will deliver rental yield or capital growth. Let to Buy vs Buy to Let: what’s the difference? Let to Buy vs Buy to Let: what’s the difference? In Let to Buy, an existing residential home is converted into a rental property while a new home is purchased to live in. Buy-to-let typically involves purchasing a property specifically for rental purposes from the outset. What are the lending criteria for Let to Buy mortgages Lenders assess income stability, credit history, property value, and existing mortgage balance. Stress testing is commonly applied to ensure affordability under higher interest scenarios. Debt-to-income ratios and overall exposure to mortgage commitments are also reviewed. How much equity or deposit do you need? Most lenders require sufficient equity in the existing property, often around 25% or more after refinancing. For the new residential mortgage, a deposit is typically required, usually starting from 10% to 25%, depending on risk profile and lender policy. How do lenders assess rental income? Rental income is usually assessed using a stress-tested calculation, where expected rent must cover 125% to 145% of the mortgage payment at a notional interest rate. Some lenders may adjust this requirement based on tax band or portfolio size.