Buy-to-let landlords are facing a second wave of mortgage rate increases from the UK's largest lenders this week, driven by swap rates climbing above 4.7%, a level that has forced repricing across products from NatWest, Santander, HSBC, Lloyds, Nationwide and TSB.
The latest moves follow an initial round of hikes at the start of September. Within Santander's BTL range, two-year fixed rates have risen by up to 45 basis points and five-year fixed rates by up to 40 basis points, changes that took one of the last remaining sub-5% products off the market.
HSBC increased rates across its BTL purchase and remortgage ranges from 15 September, including fee-saver, standard and Premier Exclusive products at multiple loan-to-value tiers. Nationwide raised selected fixed rates by as much as 30 basis points.
Aaron Strutt, product and communications director at Trinity Financial, said: "A price hike of 45bps on the two-year fixes and 40bps on the five-year fixes is going to come as a bit of a shock to customers. I can't remember the last time five of the big six lenders hiked their rates on the same day."
Average two-year fixed BTL rates stood at 5.32% on 14 September, up from 5.29% at the start of the month, according to Moneyfactscompare.co.uk. Average five-year fixed BTL rates reached 5.70%, up from 5.66% on 1 September. Across both residential and BTL products, the average two-year fixed mortgage rate has risen by 89 basis points since the start of March 2026, from 4.84% to 5.73% as of 15 September.
Rachel Springall, finance expert at Moneyfactscompare.co.uk, said: "A second wave of mortgage rate hikes has begun from the major banks in reaction to growing concerns surrounding inflationary pressures. Swap rates have climbed above 4.70%, leading lenders such as NatWest, Santander, HSBC and TSB to increase selected fixed rates for the second time this month. It is highly likely other lenders will follow suit to adjust rates, and with some deals withdrawn from the market, it is expected that any returning deals could well be priced higher."
The scale of repricing since early 2026 carries particular weight for the estimated 750,000 households currently on fixed rates below 3% that are set to expire this year, according to Bank of England data. Many of those borrowers, including portfolio landlords who fixed at historically low rates in 2021 and 2022, are now rolling into a market where BTL pricing has moved substantially higher.
Five-year swap rates climbed above 4.5% in early September, their highest level in around three years, with two-year swap rates also rising sharply. Bank of England Governor Andrew Bailey told MPs on 8 September that UK mortgage rates are now around 0.75 percentage points higher than when the Middle East conflict began, the largest increase in the G7, with the possible exception of Japan.
Springall added: "The average two-year fixed mortgage rate is at its highest point since June, with the average five-year fixed back up to levels not seen since April. This will be hugely disappointing news for borrowers."
