Interest rate movements do not just change your monthly payment. They change your entire refinance strategy. After the Iran conflict sent swap rates sharply higher from late February 2026, mortgage rates have been coming off their peak - but the trajectory is uneven, and the next Bank of England decision on 18 June 2026 will tell us a great deal about where fixed rates are heading next.
What Drove Rates to Their War-Time High?
The US-Israeli military action against Iran began on 28 February 2026 (Contractor UK, March 2026). Iran's announcement that the Strait of Hormuz - which handles around 20% of global oil supplies (Contractor UK, March 2026) - was closed triggered the largest energy supply disruption in recent history. Swap rates, which drive the fixed-rate pricing lenders use, spiked immediately.
Average 2-year fixed mortgage rates climbed from around 4.79% pre-conflict to a peak of approximately 5.56% (ContractorUK, May 2026). Five-year fixed rates followed a similar path, peaking near 5.68% on average (Uswitch, 30 May 2026). For a landlord running a portfolio of five to twelve properties, that kind of move can flip a deal from cash-flowing to loss-making within weeks.
You can stress-test your own portfolio against current rate scenarios using Property Filter's BTL stress test calculator, which models ICR (interest coverage ratio) across different rate bands.
Where Rates Stand Now - and Why the Picture Is Mixed
Lenders began cutting in earnest through May 2026. HSBC trimmed rates by up to 30 basis points across its residential, remortgage and buy-to-let range in the week ending 8 May 2026 (Mortgage One, May 2026). Nationwide, Halifax, and Santander followed suit. By 30 May 2026, the best available 2-year fixed purchase rate had dropped to 4.40% (fees £999, Nationwide) and the best 5-year fix to 4.48% (fees £490, First Direct) (Uswitch, 30 May 2026).
That is materially below the war-peak average, but still above where the market was before the conflict. From a portfolio perspective, the leverage play here is not to assume the trend continues uninterrupted. The Bank of England held base rate at 3.75% on 30 April 2026 by a vote of 8-1, with one MPC member voting for a rise to 4% (MoneySavingExpert, April 2026). The MPC has signalled that inflation - sitting at 2.8% in April 2026 after the energy price cap reduction (ContractorUK, May 2026) - could move higher later in the year.
Fixed rates are priced from swap rates, not directly from base rate. If swap rates reassert upward pressure - which they may if oil prices spike again or inflation surprises to the upside - the current window of lender cuts could close quickly. The negotiation and finance section of the Property Filter blog has a running view on how lender pricing shifts play into deal structure.
What This Means for Portfolio Refinancing in 2026
UK Finance forecasts around 1.8 million fixed-rate mortgages maturing in 2026 (Property118, 2026), including a significant share in the investment sector. If you hold properties with deals expiring this year, the current softening in rates is relevant - but the direction is not guaranteed.
The specialist segments - limited company buy-to-let, holiday let, HMO (house in multiple occupation) - are not moving in the same direction as standard residential. Some lenders in these segments have actually raised pricing where funding costs or risk appetite require it (Mortgage One, May 2026). If you hold via a limited company structure, do not assume your refinancing options have improved at the same rate as headline figures suggest.
The next MPC decision publishes on 18 June 2026. If the committee holds again and signals a cut is coming, swap rates should ease further and lenders should follow. If the vote tilts toward a rise, the current cuts may reverse fast. For detailed strategy on structuring deals around rate cycles, Property Filter's property investment strategies hub covers BRRR (buy, refurbish, refinance, rent) timing across rate environments.
Run your numbers now using the Property Filter free calculators before 18 June, so you know exactly where your refinance threshold sits.
Key Takeaways
• Average 2-year fixed rates peaked at approximately 5.56% during the Iran conflict but have since eased, with best-buy deals now at 4.40% as of 30 May 2026 (Uswitch)
• 1.8 million fixed-rate mortgages mature in the UK in 2026, creating significant refinancing pressure across the investment sector (UK Finance, 2026)
• The Bank of England held base rate at 3.75% on 30 April 2026 - the next decision is 18 June 2026, which will set the tone for the second half of the year
• Specialist BTL products (limited company, HMO, holiday let) have not followed the same downward rate trajectory as standard residential deals
