UK Inflation 3.1% as Mortgage Rates Rise Before BoE Vote

Quick Answer

UK CPI inflation rose to 3.1% in August 2026 — the highest level since March — driven by higher energy prices from the US-Iran conflict and oil above $100 a barrel. The print lands a day before the Bank of England rate decision on September 17, with markets pricing only a 35% chance of a September hike but an 80% probability of a November move. UK 2-year fixed mortgage rates have climbed from 4.84% in March to 5.73% in mid-September.

Last verified: Sep 16, 2026.

At a glance

• UK CPI August: 3.1% YoY (from 2.9% in July), 5-month high
• Core inflation: 2.6% for fourth consecutive month
• BoE base rate: 3.75% held since December 2025
• September hike odds: 35% priced
• November hike odds: 80% priced
• Average 2-year fixed mortgage: 5.73% (+89 bps since March)
• 10-year gilt yield: Above 5.25%, highest since August 2007

UK inflation August 2026: what drove the 3.1% print

The August 2026 inflation print was energy-driven, not broad-based.

UK Consumer Prices Index inflation rose to 3.1% in August 2026 from 2.9% in July, the highest level since March 2026, according to the Office for National Statistics. The driver was higher energy prices flowing through from the US-Iran conflict and Brent crude trading briefly above $100 a barrel through the Strait of Hormuz. Gas and electricity bills rose on wholesale energy price spikes, while motor fuel costs climbed roughly 4–5 pence per litre month on month (Office for National Statistics, September 16, 2026).

Core inflation, which excludes volatile food and energy prices, held at 2.6% for the fourth consecutive month — a positive signal that the headline jump is energy-driven rather than reflecting broad domestic price pressure. Services inflation remained sticky at 4.7% year on year, reflecting strong wage growth in healthcare, hospitality, and professional services.

What the Bank of England will do on September 17

The Monetary Policy Committee is widely expected to hold the base rate at 3.75%, but the path beyond that has tightened materially.

Investor expectations have shifted toward further Bank of England hikes after the August CPI surprise. Money markets are now pricing a 35% probability of a 25-basis-point hike at the September 17 meeting and an 80% probability of a hike by the November meeting. The next meeting after that is December 18, by which point investors are pricing a virtual certainty of one more hike to a peak of 4.0–4.1% (Mortgage Introducer, September 16, 2026).

Bank chief economist Huw Pill was among three MPC members who voted for a hike at the July meeting (6–3 split). Pill argued in a September 7 speech that a 25-basis-point hike to 4% would send a "clear and unambiguous signal" on inflation risks and warned that delay risked a "bias to the status quo" as energy-related pressures persisted. Governor Andrew Bailey has taken a more cautious tone, citing continued uncertainty over the Middle East (Bank of England, September 16, 2026).

How UK mortgage rates have moved in 2026

The average 2-year fixed mortgage rate has climbed 89 basis points since March 2026.

Since the start of March 2026, the average 2-year fixed mortgage rate has risen from 4.84% to 5.73%, adding £131 to monthly mortgage repayments, or £1,572 per year, on a £250,000 mortgage over 25 years. A further 0.25% rise, to 5.93%, would add another £38 per month, or £456 per year, on the same terms. The Moneyfacts Average New Mortgage Rate now stands at 5.68%, up from 5.59% in August and 4.90% in March (Moneyfacts, September 16, 2026).

Major UK lenders including NatWest, Santander, HSBC, Lloyds Bank, TSB, and Nationwide have raised selected fixed rates twice since early September. The 2-year fixed at 75% loan-to-value rose from 4.20% in December 2025 to 4.92% by July 2026, even as the Bank Rate held at 3.75% — illustrating the gap between fixed pricing (swap-rate-driven) and variable pricing (base-rate-driven).

The 10-year gilt yield: the real driver of fixed mortgage rates

UK 10-year gilt yields above 5.25% explain why fixed mortgage rates keep climbing even when the Bank of England holds.

Two-year gilt yields have climbed above 4.5% and ten-year yields above 5.25%, their highest level since August 2007. Gilt yields feed directly into swap rates, which lenders use to price fixed mortgages, meaning further bond-market movement could continue to influence fixed pricing regardless of the BoE decision itself. A sustained 10-year gilt above 5% locks the 2-year fixed mortgage rate above 5.5% for the next 6–12 months (Mortgage Introducer, September 16, 2026).

Investors betting that UK rates could hit 5% by November 2027 — five hikes from the current 3.75% — are pricing a meaningful inflation persistence scenario. Economists disagree: Peel Hunt's Kallum Pickering expects the Bank to hold for the rest of 2026 before cutting twice in 2027 once inflation risks fade. Either way, fixed mortgage rates stay elevated through at least mid-2027.

What enterprise buyers should do next

Three actions for UK mortgage borrowers, brokers, and lenders in September 2026.

1. Borrowers should request rate holds immediately. UK borrowers with mortgage fixes expiring within 6 months should request 90–120 day rate holds from at least three lenders. Major lenders offer these holds without fees, and they protect against further rate increases during a November BoE hike that 80% of investors expect.
2. Brokers should pre-emptively stress-test borrowers. Mortgage brokers should model the impact of a 5.93% 2-year fixed rate on client affordability, ensuring borrowers can absorb +£38 per month per £100,000 of mortgage balance. Stress-tested clients will survive the November MPC vote and the subsequent refi wave without payment shock.
3. Lenders should tighten affordability criteria for new originations. UK mortgage lenders should tighten affordability stress rates from current 6.5–7.0% to 7.5–8.0% for new originations, given that the average 5-year fixed will likely be 5.5–6.0% by Q2 2027. This protects lenders from the upcoming refi wave and keeps loan books compliant with PRA underwriting standards.

What to watch next

Three near-term datapoints. First, the September 17 Bank of England rate decision — a 25-basis-point hike would be a hawkish surprise and likely push 2-year fixed rates above 5.85%. Second, the September 30 UK GDP print — a weak reading (below 0.1% QoQ) could pull gilt yields back below 5% and trigger modest mortgage rate relief. Third, the November 5 MPC meeting — by which point the Bank will have October CPI (released November 19, but the meeting will use data available by early November) and the Chancellor's October 28 first Budget. Markets are pricing an 80% hike; if the BoE holds, gilts and mortgage rates would sell off 20–30 basis points on relief.

Photo: Scan by NYPL, PUBLIC DOMAIN, via Wikimedia Commons (https://upload.wikimedia.org/wikipedia/commons/1/11/A_view_of_the_Bank_of_England%2C_Threadneedle_Street%2C_London_%28NYPL_Hades-280166-1253467%29.jpg?utm_source=commons.wikimedia.org&utm_campaign=imageinfo&utm_content=original)