Rising mortgage costs threaten to dampen activity in the autumn property market as major lenders reprice fixed-rate deals in response to higher wholesale funding costs. HSBC, Barclays and NatWest have all increased selected mortgage rates since the start of September, while other lenders have also reviewed their pricing as swap rates moved higher.
The changes come at an important point in the housing calendar. Autumn is traditionally a period when estate agents and sellers hope to see activity strengthen following the summer, but renewed pressure on borrowing costs could constrain what buyers can afford. Even relatively small increases in mortgage rates make a noticeable difference to monthly repayments. Moneyfacts calculated that a borrower taking a £250,000 repayment mortgage over 25 years would see monthly repayments rise by around £38 if the interest rate increased from 5.63% to 5.88%. A standard repayment calculation puts the increase at about £37.78 a month, taking payments from roughly £1,555 to £1,592. That is an additional cost of around £453 a year before rounding.
For buyers already operating close to lender affordability limits, increases of that size can reduce the amount they are able to borrow or force them to reconsider their property budget.
Fixed-rate mortgage pricing is closely influenced by swap rates, which reflect financial-market expectations for future interest rates and form an important part of lenders’ funding and hedging costs. Moneyfacts also reported that the two-year swap rate had risen to around 4.26% by 3 September, compared with about 4.06% a month earlier. Five-year swaps had also increased, from roughly 4.16% to 4.36%. That movement has narrowed the margin available to lenders offering aggressively priced fixed-rate mortgages.
Earlier in the year, some of the largest high street banks were offering their cheapest deals at margins of around 0.29 percentage points above the two-year swap rate. When swaps rise quickly, those margins can become difficult to sustain. Lenders can respond by raising rates, withdrawing products or temporarily reducing the range of deals available. Family Building Society provided a clear example in September, withdrawing all of its fixed-rate mortgage products on 4 September after a significant increase in swap rates. It later relaunched its fixed-rate range on 16 September following repricing.
The latest repricing has so far been less severe than the disruption seen earlier in 2026. In March, more than 1,500 mortgage products disappeared from the market after a sharp rise in swap rates, according to Moneyfacts. That represented roughly a fifth of available mortgage products at the time. The pressure followed a major increase in energy prices and inflation expectations after the escalation of conflict in the Middle East.
September’s changes have been more measured. Although a number of large lenders have raised selected rates, the scale of withdrawals has remained well below that seen in March. That distinction matters for borrowers. A market in which lenders are gradually repricing is very different from one in which large numbers of products disappear within days. Even so, the direction of travel is likely to concern buyers who had been expecting mortgage costs to fall during the autumn.
Inflation concerns remain central
The latest mortgage-rate increases take place against a broader backdrop of renewed inflation pressure. The Bank of England said in September that the prolonged conflict in the Middle East had pushed crude and refined energy prices higher and increased upside risks to inflation. Official data from the Office for National Statistics showed UK consumer price inflation rising from 2.9% in July to 3.1% in August, with motor fuels making the largest upward contribution.
These developments have affected expectations for future interest rates, which in turn feed into swap markets and mortgage pricing. At its September meeting, the Bank of England kept Bank Rate at 3.75%, although three members of the Monetary Policy Committee voted for a 0.25 percentage-point increase. The decision highlighted the uncertainty facing both lenders and borrowers. Mortgage pricing depends not only on the current Bank Rate but also on market expectations for where interest rates could move over the life of a fixed-rate deal.
Government bond markets have also come under pressure. The UK 10-year gilt yield climbed above 5% in early September and reached its highest level in around 18 years as part of a wider global bond sell-off. Rising gilt yields do not translate directly into mortgage rates, but they are another indication of tighter financial conditions and increased concern about inflation, government borrowing and future interest rates.
Buyers face tighter affordability calculations
For the housing market, the main question is how long higher borrowing costs persist. Mortgage rates influence both the monthly cost of purchasing a home and the affordability tests used by lenders. If rates rise, buyers may have to reduce their maximum offer, increase their deposit or accept higher monthly repayments. That can create knock-on effects throughout property chains. A buyer with less borrowing capacity may renegotiate an agreed price or withdraw from a transaction. Sellers may need to adjust expectations, while first-time buyers can face a larger gap between the home they want and the mortgage they can secure.
Higher rates do not automatically mean transaction volumes will fall, and individual lenders can still reduce selected products even when the wider market is moving upward. Mortgage pricing remains highly competitive, particularly for borrowers with large deposits and strong credit profiles. But the recent rise in swaps has changed the backdrop for the autumn market. Instead of entering the season with borrowing costs steadily declining, buyers and sellers are now dealing with renewed interest-rate uncertainty.
For lenders, the challenge will be balancing competitive pricing against higher funding costs. For borrowers, the practical consequence is simpler: mortgage deals are becoming more expensive just as the property market enters one of its most closely watched periods of the year.
