Property ownership does not always follow a neat path. Many homeowners buy with the intention of living in their property long term, only to face a change of circumstances that makes renting out the property more attractive. Relocation for work, upsizing for a growing family, or moving in with a partner are all common reasons. When that moment arrives, the key question in 2025 is whether to request consent to let from your current lender or to switch onto a buy-to-let mortgage.
The decision matters more than ever. With lenders enforcing tighter rental stress tests and regulators maintaining a close eye on how properties are let, choosing the wrong route can leave you with unnecessary costs, compliance issues, or even a forced product switch at short notice. This article explores both options, the risks and rewards of each, and how Willow Private Finance helps clients choose the smartest way forward.
Consent to let is essentially your lender’s permission to temporarily rent out a property that was originally mortgaged as your main residence. It is not a new mortgage product but rather a formal waiver of your existing residential mortgage conditions.
Typically, lenders allow consent to let for a defined period—often 12 to 36 months—after which you are expected to either move back in or remortgage onto a buy-to-let product. The terms can vary significantly. Some lenders charge a modest administrative fee, while others increase the interest rate or restrict the type of tenancy agreements permitted.
Consent to let is often attractive for borrowers in short-term situations. For example, someone relocating abroad for a one-year contract may find it unnecessary to move straight onto a buy-to-let mortgage when the plan is to return.
By contrast, a buy-to-let mortgage is a product specifically designed for properties rented to tenants. It is underwritten with rental yield and stress tests in mind rather than solely relying on the borrower’s personal income. Loan-to-value ratios are usually capped at 75 per cent, though private banks may allow more flexibility for high-net-worth clients.
Buy-to-let mortgages are intended as long-term arrangements. They often carry higher fees and interest rates compared to residential loans, but they also provide certainty and legitimacy. Lenders expect the borrower to be a landlord for the foreseeable future and structure the terms accordingly.
In practice, the distinction between consent to let and buy-to-let has always existed, but in 2025 the gap is more visible due to stricter underwriting.
Lenders are increasingly cautious about “accidental landlords”—borrowers who obtain consent but remain on residential rates indefinitely. Regulators are also keen to ensure rental properties meet energy efficiency and safety standards, obligations that apply regardless of the mortgage type.
With buy-to-let products, the expectations are clearer. Lenders assess rental cover ratios at stress-tested rates, require minimum equity positions, and may impose portfolio-wide affordability checks for landlords with multiple properties. By comparison, consent to let remains more flexible, but it is temporary and may not survive a lender’s policy changes over time.
The risks of each option must be weighed carefully. Relying on consent to let may look cheaper at first, but if the lender decides not to renew or increases the rate, you could be forced into a switch at short notice. That could mean scrambling to meet buy-to-let criteria that your property no longer qualifies for.
On the other hand, committing to a buy-to-let mortgage means higher upfront costs and potential early repayment charges if your situation changes again. For example, if you planned to return to your home in two years but had already switched to buy-to-let, moving back could prove complicated and expensive.
Stamp duty is also a factor. If you retain your existing home while purchasing another, you will usually pay the three per cent additional property surcharge, regardless of whether you use consent to let or switch to buy-to-let. You can reclaim this if you sell your old property within three years, but cashflow planning is essential.
Consent to let is typically best suited to short-term, transitional situations. Relocating abroad for a year, moving in with a partner while trialling cohabitation, or taking an extended travel break are all scenarios where the flexibility of consent to let is valuable. The administrative simplicity—no new mortgage product, no major underwriting exercise—can save time and money.
However, it should be treated as exactly what it is: temporary. Using consent to let for five or more years is risky and may leave you in breach of mortgage terms if the lender audits your arrangement.
For borrowers who expect to remain landlords for the foreseeable future, buy-to-let is usually the stronger option. It creates certainty, allows you to build a property portfolio legitimately, and gives you access to the full range of products designed for landlords.
This is particularly true for high-net-worth borrowers or portfolio landlords, where private banks may offer bespoke terms. For those cases, lenders may consider global income streams, offset structures, or asset-based lending. We explored this flexibility in more depth in Private Client Finance in 2025: Tailored Lending for Complex Profiles.
One of our clients in Oxford planned to move abroad for a two-year secondment. They obtained consent to let from their high street lender, which allowed them to cover the mortgage with rental income and return to their property afterwards without incurring major costs.
By contrast, a London-based investor who had outgrown their first property used a buy-to-let remortgage to release equity, which then formed the deposit on a larger family home. The buy-to-let structure gave them certainty as a long-term landlord and provided additional borrowing power for future purchases.
The choice between consent to let and buy-to-let may look straightforward, but the consequences of picking the wrong path can be expensive. At Willow Private Finance, we analyse your short- and long-term goals, assess lender policies across the whole market, and identify the route that delivers the best balance of flexibility, cost, and compliance.
For clients with complex income, international considerations, or high-value properties, we also work with private banks and specialist lenders that many brokers cannot access. That means our clients benefit from solutions tailored to their circumstances rather than off-the-shelf products.
If you’re weighing up consent to let versus a full buy-to-let switch in 2025, the right advice can save you thousands and prevent costly mistakes.

About the Author - Wesley Ranger
Wesley Ranger is a Senior Mortgage and Protection Specialist at Willow Private Finance. He has advised hundreds of clients on complex borrowing strategies, from let-to-buy and portfolio structuring to high-net-worth private banking. Wesley’s reputation is built on providing clear guidance, creative structuring, and results where other brokers struggle to deliver.
Important Notice
Willow Private Finance Ltd is directly authorised and regulated by the Financial Conduct Authority (FCA No. 588422). The information provided in this article is for guidance only and does not constitute personal financial advice.
All mortgages are subject to status and lender criteria. Property values and rental income can fall as well as rise, and tax treatment depends on individual circumstances and may change in future. Your home or property may be repossessed if you do not keep up repayments on your mortgage. Always seek tailored advice before entering into a mortgage agreement.
