THE PROPERTY FILTER TAKE
Santander raised buy-to-let rates by 40 to 45 basis points, and HSBC and Nationwide repriced at the same time (Mortgage Solutions, 14 September 2026).
A 45 basis point rise costs £900 a year, or £75 a month, on a £200,000 interest-only buy-to-let loan.
Consider running your current balance through a stress test before your fix ends, and speak to your broker about what your lender will now accept.
Santander raised its buy-to-let mortgage rates by 40 to 45 basis points, or 0.40 to 0.45 of a percentage point (Mortgage Solutions, 14 September 2026). On a £200,000 interest-only buy-to-let (BTL) loan, a 45 basis point rise costs £75 a month. HSBC and Nationwide moved at the same time, and Santander's highest buy-to-let rate, a nil-fee five-year fix, rose 40 basis points to 5.51%.
How big were the increases at each lender?
Santander's move was the largest of the three. Two-year fixes went up by 45 basis points and five-year fixes by 40 basis points. The lender has effectively pulled the last of its sub-5% rates (Mortgage Solutions, 14 September 2026). On the residential side, its 90% loan to value (LTV, loan size against property value) two- and three-year fixed rates rose 45 basis points to 5.8%. The 95% LTV two-year fix went to 6.05%.
Nationwide raised rates by up to 30 basis points from 15 September, across its first-time buyer, home mover, remortgage, switcher and additional borrowing ranges (Mortgage Solutions, 14 September 2026). Its first-time buyer rates now run from 4.64% to 5.74%, with remortgage pricing close to 6%. The funding backdrop is the one we set out in our report on swap rates hitting a three-year high.
HSBC published no basis point figure at all. It raised every two- and five-year residential fix and every two-year tracker across all LTV bands from 15 September. Its BTL two- and five-year fixes and two-year trackers moved on the same day (Mortgage Solutions, 14 September 2026). Aaron Strutt is product and communications director at Trinity Financial. He told Mortgage Solutions he could not remember the last time "five of the big six lenders hiked their rates on the same day."
What a 45 basis point rise costs on a £200,000 buy-to-let loan
Most BTL lending is interest-only, which makes this quick to work out. At 5.51%, a £200,000 interest-only loan costs £11,020 a year, or £918 a month. The increase on its own is smaller than the headlines suggest. A 40 basis point rise adds £800 a year, about £67 a month. A 45 basis point rise adds £900 a year, or £75 a month.
Across a full five-year fix, that 45 basis point difference is £4,500 in extra interest. The figure that decides whether the deal happens at all is the stress test (the higher rate a lender applies to check your rent covers the mortgage). You can put your own balance and rent through our free buy-to-let stress test calculator to see where you land at the new pricing.
Nationwide's 30 basis point move is £600 a year on the same £200,000 loan, or £50 a month, though its published ranges are residential. That is the smallest of the three increases, and it still reaches remortgage and switcher business.
What this changes for landlords coming off a fix
If your fix ends in the next few months, the cost of sitting still has gone up with everything else. A lapsed fix drops you onto the standard variable rate (SVR, the lender's default rate once a deal ends). We set out the monthly cost of a lapsed buy-to-let fix in an earlier piece.
A product transfer (switching to a new deal with your existing lender) is usually the quickest route. It is not automatically the cheapest once every major lender has moved together. Your broker can check whether the wider market beats your own lender's offer, and the negotiation and finance section of our blog covers how to frame that conversation.
One caveat on the numbers above. Only Santander published a buy-to-let figure you can work with. HSBC confirmed its BTL ranges are rising but gave no size, and Nationwide's published ranges are residential (Mortgage Solutions, 14 September 2026). Treat any BTL estimate at those two lenders as unconfirmed until the rates are live.
Key takeaways
Santander raised buy-to-let rates by 40 to 45 basis points and pulled the last of its sub-5% pricing (Mortgage Solutions, 14 September 2026).
Its highest buy-to-let rate, a nil-fee five-year fix, rose 40 basis points to 5.51%, which is £918 a month on a £200,000 interest-only loan.
A 45 basis point rise adds £900 a year, or £75 a month, on that same £200,000 loan.
Nationwide moved by up to 30 basis points, worth £600 a year or £50 a month on £200,000.
HSBC raised all two- and five-year fixes and two-year trackers across residential and buy-to-let without publishing a basis point figure.
Frequently asked questions
How much does a 45 basis point rate rise cost per month?
Which lenders raised their rates?
Are buy-to-let rates affected as well as residential rates?
What is a basis point?
