Experts are advising nearly half a million British homeowners to consider securing new mortgage deals before the Autumn Budget 2026, as mortgage rates have been rising in recent weeks. According to the Financial Conduct Authority, 487,350 fixed-rate mortgages in the UK are set to expire in the final three months of 2026. This has prompted lenders to increase mortgage rates, partly due to the ongoing conflict in the Middle East and rising swap rates—interest rates that banks charge each other when borrowing money. Major lenders like NatWest, Santander, HSBC, Lloyds Bank, and TSB have all raised their mortgage prices in response. Mortgage experts caution that predicting rates over the coming months is challenging due to uncertainty around the Chancellor’s potential announcements in the Budget and the response of the gilt market, which deals with government borrowing. Research by estate agency Yopa suggests that mortgage rates have fluctuated within a relatively stable range in recent years. However, Yopa’s CEO, Verona Frankish, noted that while there may be little immediate change in mortgage costs around fiscal events, the long-term impact of a Budget can be significant, as seen with the Truss mini-Budget in 2022, which led to a sharp rise in borrowing costs. As of 16 September, the average two-year and five-year fixed mortgage rates stood at 5.77 per cent and 5.83 per cent, respectively. The latter is the highest since November 2023. The Bank of England is expected to keep its base rate at 3.75 per cent when its Monetary Policy Committee meets on 17 September. Grainne Gilmore, head of residential at real assets advisor Cluttons, explained that swap rates have been rising due to increased tensions between the US and Iran, as well as ongoing disruptions to oil supplies through the Strait of Hormuz. However, any resolution in the Middle East or government reassurance about fiscal policy could lead to lower money-market rates and, potentially, lower mortgage rates. Mortgage advisors are urging homeowners whose deals are due to expire in the next six months to seek new offers now and consult with whole-of-market brokers to find the best deals. Andrew Montlake, CEO of mortgage broker Coreco, recommended starting the process earlier than usual, as there is little downside to reviewing options now. Michael Lawlor from the Mortgage Advice Bureau emphasized that waiting for lower rates could lead to missing out on good deals, as those who secure rates early have seen real savings. Louisa Sedgwick of Paragon Bank noted that mortgage rates are likely to remain around current levels by the end of the year, though further volatility is possible. She advised borrowers, including those in the buy-to-let market, to begin reviewing their options early.