THE PROPERTY FILTER TAKE
NatWest and Keystone Property Finance cut mortgage rates, while TSB raised theirs and Principality Building Society set out increases (Mortgage Solutions, 23 September 2026).
Run the numbers: on a £150,000 interest-only BTL loan, Keystone's BTL cut of up to 15bps is worth up to £18.75 a month, and TSB's BTL rise of up to 0.2% adds up to £25.00.
Consider asking your broker which repriced product your case sits in before you apply or switch.
Two lenders cut mortgage rates and two pushed them up. NatWest and Keystone Property Finance lowered rates, while TSB and Principality Building Society raised theirs, according to Mortgage Solutions (23 September 2026). NatWest's cuts were set to take effect from 24 September.
Which lenders cut mortgage rates?
NatWest is cutting rates by as much as 22bps (basis points, hundredths of a percentage point) across mortgages for new business (Mortgage Solutions, 23 September 2026). Its fee-free two-year fixed residential purchase deal at 60% LTV (loan to value, the loan as a share of the property's value) drops from 5.36% to 5.28%. The fee-free residential purchase deal at 95% LTV falls by 17bps to 5.73%. NatWest also cut its BTL (buy-to-let) products, but the report gives no BTL figures.
Keystone Property Finance has reduced its BTL rates by as much as 15bps (Mortgage Solutions). Its standard product at 70% LTV is now priced at 3.74%. Managing director Elise Coole said the reductions give brokers "more competitively priced options across both two- and five-year fixed rates".
Run the numbers on a £150,000 interest-only BTL loan (you pay only the interest each month, not the loan itself). At Keystone's 3.74%, your monthly payment is £467.50, because £150,000 x 3.74% / 12 = £467.50. Where a product took the full 15bps cut, that is worth £18.75 a month on the same loan. You can test your own deal in our free BTL stress test calculator.
Which lenders raised mortgage rates?
TSB has increased residential fixed product transfer rates (the new deal you move to with your existing lender) by up to 0.25% (Mortgage Solutions, 23 September 2026). Its BTL rates rose by up to 0.2%, with similar increases on additional borrowing. On the same £150,000 interest-only BTL loan, the full 0.2% rise adds £25.00 a month, or £300 a year. Our free property calculators let you rerun your figures.
Principality Building Society planned to withdraw its range by 5pm on 23 September and introduce higher-priced deals the following day (Mortgage Solutions). All its deals at 65%, 75%, 80%, 85% and 90% LTV were due to rise by 0.1%. The exception was its two-year trackers at 65% LTV, due to go up by 0.15%.
One lender's reprice is not the market. If you are mid-application, you may wish to ask your broker whether your product was repriced. Our guide to negotiation and finance covers working with brokers and lenders.
Key takeaways
NatWest is cutting rates by as much as 22bps across mortgages for new business, with its fee-free 60% LTV two-year residential purchase fix down from 5.36% to 5.28% (Mortgage Solutions).
Keystone Property Finance cut BTL rates by as much as 15bps, and its standard 70% LTV product is priced at 3.74% (Mortgage Solutions).
TSB raised residential fixed product transfer rates by up to 0.25% and BTL rates by up to 0.2%, worth up to £25.00 a month on a £150,000 interest-only BTL loan.
Principality Building Society's deals at 65%, 75%, 80%, 85% and 90% LTV were due to rise by 0.1%, with two-year trackers at 65% LTV up 0.15% (Mortgage Solutions).
Frequently asked questions
Which lenders cut mortgage rates in this round-up?
How much has TSB raised its rates by?
When did Principality Building Society change its pricing?
What does a 0.2% rate rise cost on a BTL mortgage?
