Buy to let remortgage when and how to switch

A buy to let remortgage is when you replace your existing buy to let mortgage, either with a new deal from the same lender or by switching to a different lender altogether, usually to secure a new rate, release equity, or restructure your borrowing.

There are two main routes. A product transfer means moving to a new rate with your current lender, usually with less paperwork and no fresh affordability assessment. A full remortgage means switching to a new lender entirely, which involves a full application and valuation but opens up access to the wider market. Both routes are available whether you own a single rental property or a larger portfolio.

Most buy to let mortgage deals last two to five years. Once that period ends, you're moved onto your lender's standard variable rate (SVR) unless you remortgage, and the SVR is typically higher than the rate you were paying. There are three common triggers for remortgaging a rental property.

Your fixed or tracker deal is ending

Start looking three to six months before your current deal expires. Most lenders can issue a mortgage offer this far in advance, which means you can line up a new rate to start the moment your existing deal ends, rather than dropping onto the SVR while a new application completes. Your home may be repossessed if you do not keep up repayments on your mortgage or any other debt secured on it, so it's worth acting in good time rather than letting your deal lapse.

Rates have fallen since you fixed

If the market has moved since you last fixed, it can be worth remortgaging before your current deal ends, even where an early repayment charge (ERC) applies. ERCs are usually calculated as a percentage of your outstanding balance and tend to reduce the closer you get to the end of your deal. The key question is whether the saving from a new rate outweighs the ERC cost within a timeframe you're comfortable with - an advisor can work through this calculation using your actual balance and the deals available.

You want to release equity

Landlords also remortgage to release equity for refurbishment, a deposit on another property, or wider portfolio diversification. Most buy to let lenders cap borrowing at 75% loan to value (LTV), though a smaller number will lend up to 80% in the right circumstances. If you're weighing this up against releasing equity from your own home instead, our equity release guide covers the alternative routes available to homeowners aged 55 and over.

If rising costs are becoming difficult to manage, whether on this mortgage or elsewhere, impartial guidance is available from MoneyHelper (0800 138 7777).

Buy to let remortgage rates are typically higher than equivalent residential mortgage rates, reflecting the additional risk lenders attach to rental lending. The exact premium varies by lender, loan to value, and property type, so it's worth comparing options rather than assuming a single figure applies to your situation.

Rate types generally fall into four categories, each suited to different circumstances.

Alongside the rate itself, lenders assess whether the property's rental income covers the mortgage repayment by a set margin, known as the interest coverage ratio (ICR) or rental cover ratio. Most lenders require rental income to reach at least 125% of the monthly repayment calculated at a stressed interest rate, rising to 145% for higher and additional rate taxpayers or applications made through a limited company. This stress-testing approach follows the underwriting principles set out in the Prudential Regulation Authority's standards for buy to let mortgage contracts (SS13/16).

Because the ICR is based on a stressed rate rather than your actual pay rate, a property with a modest rental yield can sometimes struggle to meet the threshold even if the numbers work comfortably at your real repayment. This is one of the most common reasons landlords are declined for a remortgage they expected to sail through, so it's worth checking your figures with an advisor before you apply.

Beyond the rate and rental cover, lenders assess several other factors before agreeing to a buy to let remortgage.

Rental income coverage

As covered above, most lenders want rental income to reach 125-145% of the stressed monthly repayment, depending on your tax position and whether you're borrowing personally or through a limited company.

Loan to value

Most lenders cap buy to let borrowing at 75% LTV, with a smaller number extending to 80% for strong applications. If your property's value has fallen, or local price growth has stalled, you may find yourself in a less favourable LTV band than expected, which can restrict your options or affect the rates available. A fresh valuation as part of the remortgage process confirms where you stand.

Personal income and credit history

Some lenders ask for a minimum level of personal income alongside rental income, particularly for first-time landlords, while others lend based on rental income alone. County court judgments (CCJs), missed payments, or defaults can narrow your lender choice, but specialist lenders do cater for landlords with a less than perfect credit history. If bad credit is a concern, our guide to remortgage with bad credit covers the options in more detail.

Property and tenancy type

Standard buy to let properties let on an assured shorthold tenancy attract the widest choice of lender. Houses in multiple occupation (HMOs), student lets, properties let to tenants on housing benefit, and short-term or holiday lets are all treated as more specialist and will narrow your lender panel, though options exist for each.

A growing number of landlords hold rental property within a limited company, often structured as a special purpose vehicle (SPV), largely because of how mortgage interest is treated for tax purposes since the Section 24 changes restricted relief for personally-owned property. Remortgaging within a limited company works a little differently to a personal buy to let remortgage.

The lender panel for limited company borrowing is smaller than for personal buy to let lending, and rates tend to run slightly higher to reflect the additional underwriting involved. Lenders will usually require personal guarantees from the company's directors, which means you remain personally liable for the debt even though the company holds the property.

If you're considering moving an existing rental property from personal ownership into a limited company as part of your remortgage, be aware that this is treated as a sale and purchase for tax purposes. It will typically trigger both a Stamp Duty Land Tax charge and a potential Capital Gains Tax liability, so specialist tax advice is essential before proceeding. You can check current thresholds on the government's Stamp Duty Land Tax page.

Remortgaging a buy to let property follows a similar process to a residential remortgage, with a few extra steps to evidence your rental income. Here's what typically happens, from checking your current deal through to completion.

If you're unsure whether to act now or hold off, ask yourself three questions. In most cases, waiting on the SVR turns out to be the more expensive option, since even a fixed rate that feels only marginally better than the SVR usually costs less once you add up the extra months of higher repayments. Your home may be repossessed if you do not keep up repayments on your mortgage or any other debt secured on it, so whichever route you choose, make sure the new repayment is one you're confident you can maintain. If you're not sure which situation applies to you, speak to an advisor rather than guessing.

Comparison websites only show a fraction of the buy to let mortgages actually available. Many specialist lenders, particularly those catering for HMOs, limited companies, or landlords with adverse credit, work through advisors rather than listing products publicly.

Advice from a Financial Conduct Authority-regulated advisor means any recommendation must be suitable for your particular circumstances, taking into account your income, existing borrowing, and plans for the property. You can check any firm's authorisation on the Financial Conduct Authority Register before you proceed.

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If you're also weighing this up against a residential switch, our remortgage guide covers the residential process, and our buy to let mortgage hub has more on getting started as a landlord.