What happened
UK borrowing costs could go up rather than down this autumn. Financial markets are now pricing an almost one in four chance that the Bank of England raises its base rate from the current 3.75 percent when the Monetary Policy Committee next meets in September. The base rate is the interest rate the Bank pays commercial banks on their reserves, and it sets the floor under almost every mortgage, business loan and savings account in the country.
The shift in expectations follows warnings that a fresh cost of living squeeze is building. Wholesale natural gas prices have climbed sharply on the back of the conflict in the Middle East and the slowdown in shipping through the Strait of Hormuz. That feeds straight into the Ofgem energy price cap, the maximum unit rate suppliers in Great Britain are allowed to charge, which is reset every three months and next changes on 1 October.
The Bank published fresh forecasts alongside its last decision on 30 July, when the committee voted six to three to hold rates at 3.75 percent. The three dissenters wanted an immediate quarter point increase. The central forecast now has inflation climbing to 3.2 percent by October and staying above 3 percent until the third quarter of 2027. In a worst case involving further escalation in the Middle East, the Bank warned inflation could peak at 4.5 percent by the middle of 2027.
The government has moved to soften the blow, scrapping the 5 percent VAT rate on domestic electricity bills in Great Britain from 1 October, the same day the new price cap takes effect. City economists still expect two quarter point rate increases before the end of next year.
Why it matters
For most of the past two years the direction of travel has been downwards. Inflation fell back from double digits, the Bank cut rates step by step, and lenders slowly reduced mortgage pricing. The prospect of a rate rise reverses that story and forces households and businesses to plan for a different autumn than the one they had budgeted for.
The mechanism running through this is energy. Gas sets the marginal price of electricity in Britain for much of the year, so a jump in wholesale gas costs raises both the gas and the electricity portion of a household bill. Energy also sits inside the price of nearly everything else, from bread baked in gas fired ovens to the diesel that moves it to the shop. That is why the Bank treats an energy shock as an inflation problem rather than a one off bill increase.
The awkward part for the Monetary Policy Committee is that this inflation is not being caused by an overheating economy. Raising rates does nothing to increase the flow of gas through the Strait of Hormuz. What it does do is stop higher energy costs feeding into wage demands and business pricing, which is the outcome the Bank fears most, described as inflation becoming entrenched.
Businesses feel it twice over. Energy intensive firms face higher input costs at the same time as borrowing becomes more expensive, which typically shows up in hiring freezes and delayed investment before it shows up in prices.
Explained simply
Think of interest rates as the brake pedal on the economy. The Bank spent two years easing off the brake. Now a fresh gust of energy inflation has hit, and it is hovering a foot over the pedal again.
Here is the chain, one link at a time. Conflict in the Middle East slows tanker traffic, so less gas and oil reaches Europe. Less supply meeting the same demand means the wholesale price goes up. Suppliers buy gas at that higher wholesale price, and Ofgem allows them to pass it on through the price cap in October.
That higher bill lands on your doormat. It also lands on the accounts of every shop, factory and haulier in the country. Some of them put their prices up to cover it. When enough of them do, the average price level rises, and that average is what the official inflation figure measures.
The Bank of England has one main lever to pull. If it raises the base rate, borrowing becomes more expensive and saving becomes more rewarding, so people and companies spend a little less. Less spending eventually cools price rises. The catch is that this lever takes roughly a year to work fully, so the Bank has to act on where it thinks inflation will be in 2027, not where it is today.
What it means for you
On energy, the safest assumption is a higher bill from 1 October. The removal of 5 percent VAT on domestic electricity partly offsets this, but it applies only to electricity, not gas, so a household with gas central heating will see less benefit than a fully electric home. If you are on a fixed tariff that ends before October, check what the standard variable rate would cost you before letting it roll over.
On mortgages, anyone with a fix ending in the next twelve months should stop assuming rates will keep falling. Two year and five year fixed deals are priced off market expectations for future base rates, and those expectations have just moved higher. Many lenders let you lock in a rate up to six months before your current deal ends, and you can usually switch for free if pricing improves.
Tracker and standard variable rate borrowers are the most exposed. A quarter point increase on a 200,000 pound tracker adds roughly 25 pounds a month to repayments. Two increases would take that to around 50 pounds.
Savers get the other side of the trade. Easy access accounts and Cash ISAs, which had been drifting down towards 4 percent, are more likely to hold their rates or edge up. If you have been considering locking money into a one year fixed rate bond, waiting until after the September meeting may be worth a few extra basis points, meaning hundredths of a percentage point.
The bigger picture
Britain has been here before. The 2022 energy shock pushed inflation past 11 percent and triggered the fastest tightening cycle in decades. The difference this time is the starting point. Inflation is around 2.6 percent rather than 11 percent, and the base rate is 3.75 percent rather than near zero, so the Bank has room to move without inflicting the same damage.
The date to watch is the September meeting of the Monetary Policy Committee, with the October Ofgem cap announcement close behind. Markets currently price a modest chance of a September move, which means any hawkish signal from Bank officials before then would reprice mortgage costs quickly.
The broader question is whether a supply driven price shock deserves a demand driven response. That argument split the committee six to three in July, and it is unlikely to be settled quietly.
