Mortgage rates in the United Kingdom experienced a significant surge this week amid escalating tensions in Iran, marking the largest increase since the onset of conflict earlier this year. The average rate for a two-year fixed mortgage reached 5.54% on Tuesday afternoon, up from 5.5% at the start of the week, while five-year fixed rates climbed to 5.57%, rising from 5.52%. These figures represent notable daily gains, the largest seen since early April, when the conflict in Iran had recently intensified.

Several major lenders adjusted their mortgage rates in response to the geopolitical developments. Santander announced it would raise rates for both homebuyers and homeowners remortgaging by as much as 0.3 percentage points starting Wednesday. This followed increases of up to 0.2 percentage points from Barclays, TSB, Halifax, and HSBC earlier in the week. Nationwide and Virgin Money had already enacted rate hikes in the previous week.

Industry experts attribute these increases to concerns about potential inflationary pressures triggered by the conflict. A disruption in the supply of oil and gas through the Strait of Hormuz—a strategic chokepoint heavily reliant on for global energy transport—could drive energy prices higher, further inflating household expenses. This potential escalation in inflation is prompting lenders to adjust borrowing costs preemptively.

Nicholas Mendes, a broker at John Charcol, noted that a 0.2 percentage point rise on a typical £200,000 mortgage with a 25-year term would increase monthly payments by approximately £23, or around £276 annually. Similarly, Stephen Perkins, managing director at Yellow Brick Mortgages, cautioned that fluctuating geopolitical risks underscore the volatility of mortgage pricing, emphasizing the need for borrowers to stay informed about market changes.

The developments reflect broader concerns about how international conflicts can reverberate through domestic financial markets, influencing key consumer costs such as mortgage rates. As the situation in Iran continues to develop, lenders and borrowers alike remain attentive to the potential for further market adjustments.