Inflation Rate MoM

The UK Inflation Rate MoM is the 1-month percentage change in the Consumer Price Index. CPIH adds owner occupiers housing costs and Council Tax to the same basket. The Office for National Statistics publishes both in Table 1 of the monthly bulletin. It differs from the 12-month rate and the index level.

Coverage spans spending in the UK on about 700 items with around 180000 quotes each month. Collection uses 141 locations mid-month plus central collection for about 150 items. Weights use spending shares in parts per 1000 and update each year. CPI excludes housing costs and is the government 2% target measure.

CPIH extends CPI with owner housing and Council Tax. The basket reflects household spending and updates weights regularly.

Prices reflect at least one working week around the mid-month pricing day. Collectors price the same day each month for consistency. Fuel prices use a weekly average across the month. Fresh produce gets an extra collection day.

Release is early morning in a mid-month window in the month after the reference period. Check the bulletin header for exact timing. Each release adds driver notes plus table and time-series datasets. The index is not revised except in exceptional cases with a correction notice.

The 12-month rate is the most common inflation gauge. The 1-month move is its building block for the annual rate. CPI is the government target measure watched by the Bank of England.

Monthly moves reflect how 12 spending divisions plus housing costs diverge. Energy, food and transport often dominate the monthly change.

• Housing and household services: rents, electricity, gas and other fuels, water and maintenance, where energy shocks often dominate.
• Transport: motor fuels, vehicle purchase and maintenance, plus air and rail fares, often the largest offsetting mover.
• Food and non-alcoholic beverages: food and drink staples, often among the top upward movers.

• Recreation and culture: package holidays and cultural goods and services, highly seasonal from air fares and holidays.
• Clothing and footwear: garments and shoes with seasonal patterns, volatile from month to month.
• Owner occupiers housing costs (OOH) (CPIH only): owning and living costs by rental equivalence, plus Council Tax.

The annual rate rises when the monthly rise exceeds the one it replaces from a year earlier. A large monthly rise can coexist with falling parts such as transport. One month never makes a trend because the index is not seasonally adjusted.

1. Collect prices: Around 180000 quotes cover about 700 items from 141 locations mid-month plus central collection for about 150 items.

1. Elementary aggregates: The Jevons index is primary as the geometric mean of price relatives. Dutot covers some items as the ratio of average prices.

1. Higher aggregation: A chained Lowe-type index combines them as a weighted average with spending shares. It chain-links twice yearly with weights updated each year from household spending lagged by two years.

1. Monthly rate: The rate uses unrounded indices and is published rounded to one decimal place. It equals change divided by the previous month times 100. Component contributions sum to the monthly rate.

1. Illustrative example: If unrounded index moves from 138.42 to 139.11, the rate is 0.5% after rounding. If food with weight 120 per 1000 rises 1.0% alone, it adds about 0.12 points.