Remortgaging a Buy-to-Let Portfolio in Summer 2026: How to Time Your Deals

The Bank held the base rate at 3.75% on 30 July, the fifth consecutive hold. What is more interesting than the headline is the vote: 6-3, with Huw Pill, Megan Greene and Catherine Mann all pushing for a rise to 4.0%. That is one more dissenter than June's 7-2 split, and a more hawkish outcome than most market pricing had assumed going into the decision. The Bank's updated forecast sees inflation peaking at 3.2% in the final quarter of 2026 before falling back over 2027 and 2028.

Practically, that means two things for a portfolio landlord remortgaging now. First, a near-term base rate cut is not obviously imminent. The next scheduled decision, on 17 September, is an interim meeting without a full Monetary Policy Report, and the next full report is not due until November. Second, and more immediately relevant, the BTL rate reversal described above is happening independently of the base rate. It is a swap and gilt market move, not an MPC one. Landlords hoping a rate cut will bail them out before their current deal ends should not build that into the plan.

The 2yr vs 5yr Decision

This is the strategic question every portfolio landlord remortgaging this summer has to answer, and it is closer than it looks.

The case for two years: you are betting that today's pricing is temporarily elevated and that a shorter commitment lets you refix sooner if conditions improve. It suits landlords who actively track the market and are prepared to go through the remortgage process again in two years' time.

The case for five years: payment certainty, fewer stress tests to pass over the medium term, and a detail many landlords miss entirely, which is that five-year fixes are often assessed more generously under the affordability rules. Standard PRA guidance under Supervisory Statement SS13/16 sets a stress rate floor of 5.5%, or the mortgage's reversion rate plus 2 percentage points if that is higher, and lenders apply this to variable-rate and short-fix applications. For five-year fixed products, many lenders instead stress-test against the actual pay rate, or the pay rate plus a small margin. The Mortgage Works, for example, has applied a stress rate of 4.00% or the pay rate, whichever is higher, on five-year fixes at 65% loan-to-value or below. That is a materially easier bar to clear than 5.5%, and it is the reason many portfolio landlords choose five-year deals even when the headline rate is not much different from a two-year equivalent.

Here is why that matters in practice. Take a property earning £1,200 a month in rent, with a £200,000 mortgage at a 4.5% pay rate. Interest at the pay rate is £750 a month, giving an ICR of 160%, comfortably clearing the 145% threshold that applies to higher-rate taxpayers holding in a personal name. Stress that same loan at the standard 5.5% floor and interest rises to roughly £917 a month, dropping the ICR to about 131%, below the 145% threshold. That property fails on a two-year deal stressed at 5.5%, but could well pass on a five-year deal stressed at, or close to, the actual pay rate. Multiply that across a ten-property portfolio near the threshold and the fixed-term choice stops being a preference and starts being the difference between a mortgage offer and a decline.

The Portfolio-Wide Stress Test Nobody Escapes

Once you hold four or more mortgaged buy-to-let properties, most lenders classify you as a portfolio landlord under PRA rules and assess affordability across the whole book, not just the property you are remortgaging. Every mortgaged property in the portfolio gets tested, using the same ICR thresholds: 125% for basic-rate taxpayers and limited company borrowers, 145% for higher-rate taxpayers in personal name, and up to 165% to 175% for additional-rate taxpayers, HMOs and multi-unit freehold blocks, depending on the lender.

A weak property elsewhere in the portfolio can, in principle, drag down a lender's confidence in the whole application, even if the property you are actually refinancing passes comfortably on its own numbers. Before you apply anywhere, run every mortgaged property in the portfolio through the stress test at 5.5%, not just the one at the top of your to-do list.

What to Actually Do This Summer

1. Audit the whole portfolio before you apply anywhere. Identify every property that fails the stress test at 5.5%, not just the ones coming up for renewal first. A property with a comfortable pay-rate ICR can still be the one that sinks a portfolio-wide application.

2. Address borderline properties before, not during, the application. Overpaying to reduce the loan, or deploying cash reserves to bring the loan-to-value down, can lift a marginal ICR above the threshold. Sort this out ahead of time rather than mid-application.

3. Use a specialist portfolio broker. High-street lenders routinely decline or restrict applications from landlords with four or more mortgaged properties. A broker with access to specialist portfolio lenders, and knowledge of which ones offer the more favourable five-year stress rate, will save time and rejected applications.

4. Move quickly once you have decided. With pricing genuinely moving week to week in the current environment, a product you were quoted last month may no longer be available, and a rate held for a few days can disappear if swap rates move again.

5. Be honest about properties that cannot be rescued. If a property fails the stress test even after overpaying, and a realistic rent increase will not close the gap, selling may be the more sensible outcome than forcing a remortgage through at the cost of the rest of the portfolio's borrowing capacity.

Model Your Own Numbers

The maths above uses round figures to illustrate the mechanism. Your actual ICR depends on your rent, your loan size, your tax position and the specific lender's stress rate, all of which vary. Run your own portfolio through the RealYield calculator to see where each property actually sits before you start applying, and always confirm current lender criteria with a specialist broker, since stress rates and thresholds vary by lender and can change without much notice.

This article is for informational purposes only and does not constitute financial or investment advice. Tax rules and legislation change frequently. Always verify current rates with HMRC or GOV.UK and seek independent professional advice before making investment decisions.