UK consumer inflation climbs to 3.4% as global CPI shows mixed signals

Britain's headline consumer price inflation unexpectedly rose to 3.4% year-on-year in December, up from 3.2% in November and slightly above the median economist forecast of 3.3%. The rise was driven in part by higher air fares and tobacco prices, underscoring the uneven composition of recent inflation dynamics and complicating the Bank of England's path on interest rates.

Across the Atlantic, US Bureau of Labor Statistics figures for December showed headline Consumer Price Index inflation at 2.7% year-on-year, unchanged from November, with a 0.3% monthly increase. Core CPI, which excludes food and energy, was reported at 2.6% year-on-year, also unchanged month-to-month on an annual basis while rising 0.2% in December. Food prices climbed 0.7% for the month, with groceries and restaurant meals both up 0.7%. Energy rose 0.3% for the month and was 2.3% higher year-on-year, while gasoline fell 0.5% month-on-month and was down 3.4% year-on-year. Shelter, the largest CPI weight, rose 0.4% in December and was up about 3.2% year-on-year.

Economists warned the US data are unusually noisy because of distortions tied to a recent government shutdown that disrupted BLS data collection. The agency carried forward some rental inflation estimates, suppressing November shelter readings and mechanically boosting December figures. That statistical quirk means the US December print contains a rebound element rather than a pure fresh acceleration in underlying services inflation. Moody's chief economist Mark Zandi also flagged policy drivers, saying tariffs had put upward pressure and that "inflation for staples, necessities, remains elevated."

In Canada, Statistics Canada reported headline CPI of 2.4% year-on-year in December, up from 2.2% in November. Officials flagged a temporary Goods and Services Tax and Harmonized Sales Tax break that began on Dec. 14, 2024; the earlier declines for exempt goods and services dropped out of the year-on-year comparison, mechanically lifting the December reading. Excluding gasoline, Canadian CPI rose 3.0% year-on-year in December, up from 2.6% the month before. Restaurant prices were a notable contributor, accelerating to an 8.5% annual gain in December. Regionally, nine provinces saw faster inflation, while British Columbia slowed largely because traveller accommodation prices plunged after an outsized spike tied to high-profile events in December 2024.

Comparisons across the three countries require caution: baskets, weights and seasonal adjustments differ, and temporary policy changes or data interruptions have materially affected headline rates. Still, a common pattern is clear: goods and energy volatility continues to dominate short-term swings while services and shelter remain stickier and more important for policy.

For central bankers, the mixed signals complicate the calibration of policy. The Bank of England may see the UK surprise as a reason to be more cautious about easing, while the Federal Reserve will likely look through some of the US rebound given methodological distortions. The Bank of Canada will face pressure to disentangle genuine demand-driven inflation from base-year tax effects. Market participants and policymakers will watch incoming monthly prints and wage and services data closely to determine whether recent upticks mark a sustained shift or temporary noise.