Most buy-to-let mortgages are taken on a fixed or tracker deal that lasts two to five years. When that deal ends, the loan usually rolls onto the lender’s standard variable rate, which is almost always higher. That is why remortgaging a buy-to-let property is a routine part of being a landlord: done at the right time, it can cut your monthly payment, release equity for your next purchase, or move you to a product that better suits how you now run your portfolio.
This guide explains when a remortgage makes sense, what it costs, how lenders assess buy-to-let applications, and the steps involved from first comparison to completion.
What Remortgaging a Buy-to-Let Property Actually Means
Remortgaging means replacing your existing mortgage with a new one, either with your current lender (often called a product transfer) or with a new lender. The property stays the same, the tenants stay the same, and the ownership does not change. What changes are the rate, the terms, and sometimes the amount borrowed.
Landlords remortgage for three main reasons: to avoid drifting onto an expensive variable rate, to borrow more against a property that has risen in value, or to restructure borrowing across a portfolio. Each reason has different costs and tax points attached, so it pays to be clear about your aim before you start comparing deals.
When Remortgaging Makes Sense
The clearest trigger is the end of your current deal. If your fixed rate finishes in the next three to six months, starting the process early means the new mortgage can begin the day the old deal ends, with no time spent on the variable rate. Many lenders let you secure a new rate several months ahead, so there is no need to wait until the final week.
Releasing equity is the second common reason. If the property has gained value since you bought it, a remortgage can free up a deposit for another purchase or fund improvements to the existing property. Borrowing more increases your monthly payment, so the rental income has to support the larger loan under the lender’s affordability tests.
A third reason is change: moving from a repayment mortgage to interest-only (or the other way round), switching a property into or out of a limited company structure with professional advice, or consolidating how several properties are financed. These moves have wider tax and legal implications, so they should never be based on the mortgage rate alone.
What a Remortgage Costs
The headline rate is only part of the picture. A typical buy-to-let remortgage can involve:
- Arrangement or product fees, which can be a flat amount or a percentage of the loan. Some lenders allow the fee to be added to the mortgage, though you then pay interest on it.
- Early repayment charges if you leave your current deal before it ends. These are usually a percentage of the outstanding balance and reduce over the deal term, which is why most landlords wait for the deal to finish.
- Valuation and legal fees. A new lender will normally need a valuation of the property, and conveyancing work to move the charge. Some products include free valuation and standard legal work.
- Broker fees, if you use a mortgage broker. Many landlords do, because buy-to-let criteria vary a lot between lenders.
Comparing deals on the total cost over the deal period, rather than the rate alone, gives a fairer picture. A very low rate with a large percentage fee can work out more expensive on a smaller loan than a slightly higher rate with no fee.
How Lenders Assess a Buy-to-Let Remortgage
Unlike a residential mortgage, a buy-to-let application is judged mainly on the property and its rent, not just on your salary. Lenders usually require the rental income to cover the mortgage payment by a margin, commonly expressed as an interest cover ratio. The required cover is often around 125% for basic-rate taxpayers and higher, up to around 145%, for higher-rate taxpayers, tested at a stressed interest rate above the actual product rate.
Lenders also look at the loan-to-value. Rates improve noticeably at lower loan-to-value bands, so a property that has risen in value may unlock better deals than the ones available when you bought. Your wider portfolio, experience as a landlord, and personal income can all come into the assessment, particularly with specialist lenders.
Because the affordability rules interact with tax, it helps to understand how the interest itself is treated. Our guide to buy to let mortgage interest tax relief explains the 20% tax credit system that replaced full deductibility for individual landlords.
Remortgaging Step by Step
The process is straightforward when it is planned:
- Check your current deal. Note the end date, any early repayment charges, and the balance outstanding.
- Decide what you need. A like-for-like switch, extra borrowing, or a structural change each lead to different products.
- Compare the market or speak to a broker. Look at total cost over the deal term, not just the rate.
- Apply and provide documents. Expect to share tenancy details, rental income evidence, tax returns and ID.
- Valuation and underwriting. The lender values the property and checks the rent supports the loan.
- Completion. The new mortgage repays the old one; if you are releasing equity, the balance comes to you.
While you are reviewing the numbers, it is worth sense-checking the wider tax picture. Our overview of buy to let taxation brings the main rules together, and our list of landlord tax deductions covers the running costs you can claim each year.
Tax Points to Check Before You Switch
A straightforward remortgage with the same or a different lender does not create a capital gains tax charge, because you have not sold the property. The areas to watch are structural: transferring a property between spouses or into a company can have stamp duty and capital gains consequences, and borrowing against a property to spend on non-property purposes does not change how the interest relief works, which follows the purpose of the original borrowing rules for landlords.
If the property has a short-term let element, the rules are different again. Our guide to furnished holiday let tax rules explains what changed in April 2025 and why the old advantages no longer apply. Whatever you change, keep your records aligned with your self assessment for property income so the figures you report match the borrowing you actually have.
Common Mistakes to Avoid
The most expensive mistake is doing nothing and sitting on the standard variable rate for months. The second is chasing the lowest headline rate without adding up fees, particularly on smaller loans. Landlords also trip up by applying before checking the rent will pass the lender’s stress test at the new loan amount, or by forgetting that releasing equity increases the payment that rent has to cover.
Finally, do not remortgage in isolation. A property portfolio works best when the borrowing, the tax position and the letting plans are reviewed together, ideally a few months before each deal ends, so you are choosing from the whole market rather than whatever is available at the last minute.
