When a buy-to-let fixed rate ends, switch to a new deal with your lender (a product transfer) or remortgage with another. Like-for-like refinancing is easier: the Bank of England’s buy-to-let underwriting rules do not apply if you borrow no more than you owe. Raising extra money means passing the full rental stress test again.
How big is the remortgage market in 2026?
Refinancing dominates the mortgage market this year. UK Finance forecasts £77 billion of external remortgaging in 2026, up 10%, and £261 billion of product transfers, up 2%, across all mortgages. By June, £41 billion of remortgages and £143 billion of product transfers had been completed. Bank Rate stood at 3.75% at the September 2026 decision, with the next announcement due on 5 November 2026.
UK mortgage refinancing in 2026
Like-for-like or extra borrowing?
The PRA’s supervisory statement SS13/16 says its expectations do not apply to buy-to-let remortgages where there is no additional borrowing beyond the amount outstanding, whether with the same lender or a different one. Arrangement, professional and administration fees can be added without counting as extra borrowing.
Borrow more, to release equity or fund works, and the new loan must meet the full test: an interest coverage ratio, typically at least 125%, at a stressed rate of 5.5% or more unless you fix for five years. Our stress test guide includes a worked example. Lenders set their own criteria, so check them. When you choose a new fix, the PRA also expects lenders to consider the risk of refinancing at the end of it: a short deal now means facing the market again sooner.
Same balance or extra borrowing?
| Same balance | Extra borrowing | |
|---|---|---|
| PRA underwriting expectations | Do not apply | Apply in full |
| Fees added to the loan | Not counted as extra borrowing | Part of the new loan |
| Rental stress test | Lender’s own criteria | ICR at a stressed rate |
| Typical aim | New rate when a fix ends | Release equity or fund works |
What costs should you compare?
Compare the total cost over the deal period, not just the rate: product or arrangement fees, valuation and legal costs if you move lender, and any early repayment charge if you leave before your current deal ends. Your mortgage offer sets out those charges. Mortgage interest is not deductible for individual landlords; it earns a basic rate tax credit, so a lower rate helps your cash flow more than your tax bill.
Your loan-to-value matters again at remortgage: if the property has risen in value, a lower LTV can open better deals, as explained in our guide to deposits and LTV.
What do lenders check before you switch?
Lenders take account of the rent you actually receive and your costs as a landlord, so keep your paperwork in order: tenancy agreement, rent statements and up-to-date safety certificates. A property you cannot legally let, such as one rated below EPC band E without an exemption, puts the rent itself at risk; our landlord obligations guide lists the checks.
This is general information, not financial advice: speak to an FCA-authorised mortgage adviser about your own circumstances. Your property may be repossessed if you do not keep up repayments on your mortgage.
A remortgage timeline
- Note your end dateFind when your fixed rate and any early repayment charge end.
- Check your numbersCurrent balance, property value, rent and LTV.
- Compare both routesProduct transfer offer versus other lenders, total cost.
- Gather documentsTenancy, rent statements, EPC and safety certificates.
- Take adviceAn FCA-authorised adviser can compare the market.
FAQs
Do I have to pass the stress test again when I remortgage?
Not under the PRA’s expectations if you do not borrow more than you already owe. Individual lenders still apply their own criteria, so the rent and your circumstances will be reviewed.
Can I add the fees to my new loan?
The PRA allows arrangement, professional and administration fees to be excluded when deciding whether a remortgage involves extra borrowing. Whether a lender lets you add them is set out in its offer.
Is a product transfer always cheaper?
Not necessarily. Another lender may offer a lower total cost, even after legal and valuation fees. Compare the full cost of each offer over the deal period.
Start comparing deals well before your fix ends. Refinancing the same balance avoids the full stress test; borrowing more means passing the ICR again at 5.5% or more.
References
- Supervisory Statement 13/16: Underwriting standards for buy-to-let mortgage contracts — Bank of England, Prudential Regulation Authority (September 2016): ICR, stress rate, portfolio landlords.
- Mortgage lending in 2026: mid-year health check — UK Finance (1 September 2026): forecasts and lending to June 2026.
- The interest rate (Bank Rate) — Bank of England: Bank Rate 3.75%, next decision 5 November 2026.
- Income Tax when you rent out a property: working out your rental income — GOV.UK / HMRC (updated 19 March 2025): allowable expenses, finance costs, companies not affected.
