Consumer prices · 331 categories · latest 2026-09-01
The same category from more than one publisher. The national statistics office is the record; the IMF's series are its own compilation and can differ in definition, coverage and vintage.
CPIH includes owner occupiers' housing costs; CPI does not. ONS publishes both.
Frequencies are separate source series, not interchangeable observations. Annual measures retain their source definitions.
Sources: Office for National Statistics licensed under the Open Government Licence v.3.0 (as of 2026-09-02); International Monetary Fund (as of 2026-09-01). Collected by Living Inflation Data, HBS Innovations in Economic Measurement (IEM) Lab www.iemlab.org.
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How the selected source divides its 100% consumer basket. Select a bar to reveal the next level.
6 recorded findings for this country, shown exactly as in the full quality register.
| Country | Source | Periods | Status | Series | Found | Detected by |
|---|---|---|---|---|---|---|
| United Kingdom | ONS | 1991-04-01 | suppressed | GBR.CPIH_ONS_CP049_* | 2026-09-02 | Possible index rebasing |
| An administered price cut, and the same shape as the 2023 gas cap: flat, one step, flat. Council tax and rates reads 52.6 for January, February and March 1991, 37.1 in April, then 37.0 for the months after -- a 29.5% fall with no drift on either side. A re-referencing would rescale the whole series, not step it once in the middle, and the months before and after are on the same scale as each other. The cause is not in the data but is not in doubt either: the community charge was cut by 140 pounds a head from April 1991, funded by the VAT rise announced that March. This series exists only in CPIH -- council tax is outside the CPI basket -- which is why one flag appeared here without a CPI twin. | ||||||
| United Kingdom | ONS | 2023-07-01 | suppressed | GBR.CPI_ONS_CP0452_*, GBR.CPI_ONS_CP04521_*, GBR.CPIH_ONS_CP0452_* +1 more | 2026-09-02 | Possible index rebasing |
| A real fall in a regulated price, not a change of base. UK gas drops 25.2% in July 2023 (225.90 -> 168.90; natural gas 25.8%) and stays down, which is the shape base_break is built to suspect. Three things say it is a price movement. First, it dilutes correctly up the weighted hierarchy: gas -25.2%, its parent electricity/gas/other fuels -15.1%, housing and fuels -4.1%, all items -0.4%. A re-referencing does not do that -- the ONS would re-reference the parents with the child, and the aggregate would not move at all. Second, the ONS's own published month-over-month figure agrees, and for this source that is independent evidence rather than arithmetic: it is computed from unrounded levels and disagrees with the ratio of the published index at 31.7% of cells. Third, the level is FLAT either side (228.0, 228.0, then 169.3, 169.3, 169.3), which is what an administered price resetting looks like and not what a re-referencing looks like. The 'four series break together' line in the flag counts GAS and natural gas twice, once for CPI and once for CPIH -- one category, not four. | ||||||
| United Kingdom | ONS | 1991-03-01, 2026-06-01 | suppressed | GBR.CPI_ONS_CP0453_*, GBR.CPIH_ONS_CP0453_* | 2026-09-02 | Possible index rebasing |
| Heating oil tracking crude, twice, and in both cases a trend rather than a step. March 1991: 51.4, 50.0, 39.9, 37.5, 38.4 -- the fall continues into the following month and then partially recovers, which no change of base does. June 2026: 324.9, 264.3, 211.3, 209.1 -- three consecutive monthly falls, of which the check flags only the one that crosses -20%. Liquid fuels carry a small weight, so the dilution up the hierarchy is small but present and in the right direction (-1.1% at electricity, gas and other fuels in 1991). A base change would be one step and permanent; both of these are runs. | ||||||
| United Kingdom | ONS | whole series | suppressed | GBR.CPI_ONS_CP01116_*, GBR.CPIH_ONS_CP01116_*, GBR.CPI_ONS_CP01152_* +9 more | 2026-09-02 | Possible index rebasing, Single-month index anomaly |
| Not defects: the tail of a distribution the thresholds were not calibrated on. Both checks fire beyond 20% -- outlier_value at 20% from the midpoint of a month's neighbours, base_break at a 20% one-month fall -- and both numbers were tuned on the IMF's COICOP DIVISIONS. The ONS publishes four levels below that, and volatility rises monotonically with depth. Measured over every monthly index cell held, as deviation from the midpoint of its neighbours: median 0.15% at the UK all-items index, 0.21% at division, 0.25% at group, 0.35% at class and 0.55% at subclass, with the 99.9th percentile rising from 1.4% to about 25%. A fixed 20% rule therefore selects roughly the top 0.1% of ordinary movement at subclass level whether or not anything is wrong; at division level the same rule was near-silent, which is where its precision came from. The individual shapes agree. Binding services and e-book downloads is flagged seven times between 2017 and 2026, spiking 21% to 67% and returning within a month or two every time -- seven events is not an event, it is a thin sample. Margarine does the same four times (109 -> 81 -> 106, and 114 -> 83 -> 106), always returning. Air and sea passenger transport are seasonal. In every case the parent category absorbs the movement and the all-items index moves by less than 1%. Neither defect the checks look for is present: a base change is permanent and these return; one bad cell happens once and these recur. Making the threshold depth-aware is the fix, and it is ROADMAP item 16. | ||||||
| United Kingdom | IMF | whole series | confirmed | GBR.CPI_INDEX.M, GBR.CPI_CP*_INDEX.M, GBR.CPI_YOY.M +3 more | 2026-09-02 | Manual |
| The series this database holds as the United Kingdom's CPI, from the IMF, is the ONS's CPIH -- a different index on a wider basket, including owner occupiers' housing costs and council tax. Found while building the ONS connector, by comparing the IMF's GBR series against both of the ONS's published indices. The index is identical to CPIH at every one of 6,019 overlapping monthly cells across all thirteen concepts (the all-items aggregate and twelve divisions, 463 months each), and matches the ONS CPI at 1,882 of the same 6,019. The gap is not rounding: CP04 (housing, water and fuels) runs up to 16.1 index points apart from the CPI, which is roughly what owner occupiers' housing costs are worth, and the all-items index up to 2.2 points. No value here is wrong -- every number is a number the ONS published -- but the NAME is, and a reader comparing 'UK CPI' from this database against the ONS's headline gets a different figure with nothing to explain it. The series ids are public identifiers and are not being renamed (ARCHITECTURE section 10); the UK's actual CPI now arrives under GBR.CPI_ONS_* from ons.mm23, alongside CPIH under GBR.CPIH_ONS_*. Separately, the IMF's published year-over-year figure for GBR is the ratio of its own ROUNDED index at all 451 months, and agrees with the rate the ONS actually publishes in only 302 of them -- so where both exist, the ONS series is the one to quote. | ||||||
| United Kingdom | ONS | 2026-02-01, 2026-03-01, 2026-04-01, 2026-05-01, 2026-06-01, 2026-07-01 | confirmed | GBR.CPI_ONS_CP01*, GBR.CPIH_ONS_CP01*, GBR.CPI_ONS_CP02* +5 more | 2026-10-04 | Manual |
| ONS's 16 September 2026 MM23 notice identifies misclassified scanner products within food/non-alcoholic beverages and alcohol/tobacco during February-July 2026. Headline and division growth rates are unaffected; some lower aggregates differ by up to 0.2 percentage points. ONS explicitly leaves historical low-level indices unrevised under its correction policy. Preserve those published cells, including in derived rates; do not substitute the impact workbook as revised observations. Official notice reviewed 2026-10-04: https://www.ons.gov.uk/economy/inflationandpriceindices/adhocs/3621datasetaccompanyingtheproductclassificationerrorcorrectionfebruarytojuly2026 | ||||||