Buy-to-let remortgage explained

Remortgaging a buy-to-let means switching to a new deal at the end of your current one, either with your existing lender (a product transfer) or a new lender. The catch in 2026 is the rental stress test, applied at higher stressed rates, so a rent that once covered easily may now support a smaller loan. Options include a product transfer that skips the full re-test, a five-year fix with a gentler test, or top-slicing with personal income.

Why timing matters right now

Around 1.8 million fixed-rate mortgage deals are scheduled to end in 2026[UK Finance], and landlords are part of that wave. Many took cheap fixes years ago and now face both higher rates and a tougher rental cover test. The result is that some buy-to-let remortgages no longer pass on the rent alone, so planning the route well ahead of your deal ending is worth real money.

If the stress test is the problem

Switch or stay

The honest answer is that it depends on your numbers, and the headline rate is only part of it. The decision between staying (product transfer) and switching (full remortgage) is the same question residential borrowers face, and we walk through it on should you switch or stay and remortgage vs product transfer.

Common questions

Why is my buy-to-let harder to remortgage now?

Because the rental stress test is applied at today's higher stressed rates. A rent that comfortably covered a 2% era mortgage may not stretch to cover the stressed rate a lender uses now, so the same property can support a smaller loan than it did at your last remortgage.

What if my rent no longer passes the stress test?

You have options: stay with your current lender on a product transfer (which usually does not re-apply the full affordability test), reduce the loan, switch to a lender with a more generous test such as a five-year fix or a company product, or in some cases use top-slicing where personal income supports the shortfall. A broker matches the route to your case.

Can I release equity from a buy-to-let?

Yes, by remortgaging to a higher loan amount, subject to the rental stress test on the new, larger loan and the lender's maximum loan-to-value (commonly around 75%). Releasing equity to fund another deposit is a common way landlords grow a portfolio.

Switch lender or take a product transfer?

A product transfer with your existing lender is quick and skips the full affordability re-test, which helps if your numbers are tight. Switching lender can get a better rate or release equity but means a fresh application and stress test. The cheapest sticker rate is not always the best outcome once fees and the stress test are included.

AP

Adam Parker

Founder, MortgageExplained, MortgageExplained

Adam spent nearly a decade as a mortgage adviser at Just Mortgages, with further experience in commercial finance. He is CeMAP and CF qualified. He built MortgageExplained to do one thing well: explain mortgages in plain English, then introduce you to a regulated broker when you are ready. Every page is written and reviewed by Adam.

Last reviewed: 29 June 2026

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