thesisPrototype

Government data

UK CPI Annual Rate, June 2026

What will the ONS Consumer Prices Index (CPI) all-items 12-month annual rate for the UK be for June 2026, not seasonally adjusted, in the first print?

Overdue · was due Jul 21, 2026

The resolver has no route for this target's reference. The target was registered with a generic source link rather than a resolver binding.

NO_ROUTE_GENERIC_URL · resolver status as of Oct 7, 2026

Forecast

2.9%
2.5%–3.3%
80% prediction interval
gpt-5.5Run record ↗

Cumulative probability

Chance that the outcome is at or below each value.

0%25%50%75%100%1.9%2.9%3.9%Forecast value

Shaded band: 80% interval (2.5%–3.3%). Dashed line: point estimate (2.9%).

Derived from the point estimate and 80% interval; the agent did not report a full distribution.

Analysis

§UK CPI June 2026 First-Print Forecast

Framing and exact resolver: target identity is the ONS Consumer Prices Index all-items 12-month annual rate for June 2026, the non-seasonally-adjusted CPI headline rate. The supplied ledger contract, however, binds the resolver URL and sourceBinding to the May 2026 bulletin and 2026-05 field while the slug/dataPointId say June 2026. I keep the registered slug, URL, date, and dataPointId fields for contract consistency and flag the discrepancy rather than silently changing the target.

▸ Reported tool use: official.lookupmodel report
Opened ONS Consumer price inflation, UK: May 2026 and read release metadata plus Table 1.
↳ Fetched ONS numbers: release date 17 June 2026; next release 22 July 2026; May 2026 CPI index 142.4; May 2026 CPI 12-month rate 2.8%; May 2026 CPI 1-month rate 0.2%; April 2026 CPI 12-month rate 2.8%.
▸ Reported tool use: official.lookupmodel report
Read ONS May 2026 Table 1 recent CPI annual-rate history for the same CPI variant.
↳ Fetched same-variant CPI annual rates: May 2025 3.4%, Jun 2025 3.6%, Jul 2025 3.8%, Aug 2025 3.8%, Sep 2025 3.8%, Oct 2025 3.6%, Nov 2025 3.2%, Dec 2025 3.4%, Jan 2026 3.0%, Feb 2026 3.0%, Mar 2026 3.3%, Apr 2026 2.8%, May 2026 2.8%.
▸ Reported tool use: official.lookupmodel report
Read ONS May 2026 CPI component table and commentary for current-release pressure points.
↳ Fetched ONS component numbers: May 2026 CPI services annual rate 3.7%, CPI goods annual rate 2.0%, core CPI 2.6%, transport 6.8%, food and non-alcoholic beverages 2.2%, motor fuels 24.6%, petrol 157.4 pence per litre.
▸ Reported tool use: official.lookupmodel report
Opened ONS Consumer price inflation, UK: April 2026 to cross-check prior month dynamics and base effects.
↳ Fetched ONS April numbers: April 2026 CPI annual rate 2.8%, March 2026 CPI annual rate 3.3%, April 2026 CPI monthly rate 0.7%, April 2025 CPI monthly rate 1.2%, April 2026 CPI index 142.1, June 2025 CPI index 138.9.

Base rate/reference class: for one-month-ahead forecasts of this exact ONS CPI annual-rate series, the strongest base rate is persistence plus recent monthly changes. The latest three headline CPI annual rates were 3.3%, 2.8%, and 2.8%, averaging 2.97% if using March-May but 2.87% if downweighting March's pre-April energy-price-cap step. Since the June 2025 base month already had a 0.3% monthly CPI rise, June 2026 needs a monthly rise materially above 0.3% to push the annual rate above 2.9%.

Prior/update/interval: persistence prior is 2.8% from the latest ONS first-print headline, with a reference class of 12 successive monthly changes in the same CPI annual-rate series from May 2025 to May 2026: +0.2, +0.2, 0.0, 0.0, -0.2, -0.4, +0.2, -0.4, 0.0, +0.3, -0.5, 0.0 percentage points. The sample standard deviation of those changes is sigma = 0.27, so an 80% normal half-width is roughly 1.28*sigma = 0.35 percentage points. Level/index arithmetic: May 2026 CPI index 142.4 divided by June 2025 CPI index 138.9 gives 2.52% before June's monthly change; adding a plausible +0.3% to +0.4% June monthly move implies about 2.8% to 2.9%. I add one combined +0.1 percentage point current-pressure adjustment for services, transport, and possible fuel pass-through, giving a 2.9% point estimate; the 80% interval is symmetric before rounding and rounded outward to 2.5% to 3.3% for one-decimal first-print risk.

Current-release adjustment: the level effect from April's energy-price-cap fall has already entered the annual rate, while May's headline was unchanged at 2.8%. Transport and services are the main upside mechanism, but goods, food, and household-services easing keep the central forecast below 3.0% unless June air fares, fuel, or package holidays are unusually strong.

Counter-considerations: upside risk is a renewed fuel and air-fare jump after the Middle East shock, which would land above the interval if June monthly CPI exceeded about 0.75%. Downside risk is another broad goods and food disinflation month plus falling domestic energy or fuel prices, which would land below the interval if the June monthly CPI change was below about -0.05%. Outside the interval would most likely require a large transport-energy surprise or an unusually broad retail discounting month.

Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

Key drivers

  • May CPI annual rate held at 2.8% after April's fall
  • June 2025 base month had CPI index 138.9 and 0.3% monthly inflation
  • May 2026 CPI index was 142.4, so a normal June monthly rise implies about 2.8% to 3.0% annual inflation
  • Services inflation rose to 3.7% and transport inflation to 6.8%, adding upside pressure
  • Food, household services, and goods inflation were easing, limiting the upside

Tool evidence

This run has no captured tool responses. “Reported tool use” in the analysis is the model’s account, not an archived tool response.

Sources and resolution

Official source
Office for National Statistics, Consumer price inflation, UK: May 2026
Resolution date
July 21, 2026· outcome not recorded
Resolution rule
Resolve according to the registered ledger target: use the first ONS-published CPI all-items 12-month rate tied to dataPointId ons.cpi.annual_rate.june_2026.first_print, in percent rounded to one decimal place, with first-print policy and no later revisions. The registered sourceBinding points to the May 2026 CPI bulletin and field official_release:ons:cpi:2026-05:cpi_annual_rate despite the June 2026 target identity; this forecast preserves the ledger resolver fields and states the apparent May/June discrepancy for audit.
Run details

The analysis is the model’s written report. Tool-use descriptions in that report are model claims; the activity artifacts contain the execution record.

thesis.analyst · gpt-5.5 · v2.2.0

pre-submit review · completed

Draft is mostly publication-ready methodologically, but its resolver fields intentionally diverge from the supplied ledger contract and should be reconciled before publication.

  • blocking resolver: The JSON fields use June 2026 bulletin URL/text and 2026-07-22 resolutionDate, while the canonical ledger contract supplied May 2026 URL/sourceBinding and an expected window ending 2026-07-21.
  • warning coherence: The downside tail says below-interval risk occurs if June monthly CPI 'fell or rose by less than about -0.05%', which is internally awkward because a rise cannot be less than a negative threshold.
  • info optional_suggestion: In the compact Prior/update/interval step, separate the +0.1pp services/transport adjustment from the Middle East fuel-pass-through assumption so readers can see whether it is one combined adjustment or two effects.
  • info optional_suggestion: Consider naming whether the 80% interval is intended to be symmetric before rounding or deliberately widened for one-decimal first-print risk.

disposition accepted: Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

disposition accepted: Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

disposition not applicable: Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

disposition not applicable: Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

Activity artifacts

Complete original trace

§UK CPI June 2026 First-Print Forecast

Framing and exact resolver: target identity is the ONS Consumer Prices Index all-items 12-month annual rate for June 2026, the non-seasonally-adjusted CPI headline rate. The supplied ledger contract, however, binds the resolver URL and sourceBinding to the May 2026 bulletin and 2026-05 field while the slug/dataPointId say June 2026. I keep the registered slug, URL, date, and dataPointId fields for contract consistency and flag the discrepancy rather than silently changing the target.

▸ Reported tool use: official.lookupmodel report
Opened ONS Consumer price inflation, UK: May 2026 and read release metadata plus Table 1.
↳ Fetched ONS numbers: release date 17 June 2026; next release 22 July 2026; May 2026 CPI index 142.4; May 2026 CPI 12-month rate 2.8%; May 2026 CPI 1-month rate 0.2%; April 2026 CPI 12-month rate 2.8%.
▸ Reported tool use: official.lookupmodel report
Read ONS May 2026 Table 1 recent CPI annual-rate history for the same CPI variant.
↳ Fetched same-variant CPI annual rates: May 2025 3.4%, Jun 2025 3.6%, Jul 2025 3.8%, Aug 2025 3.8%, Sep 2025 3.8%, Oct 2025 3.6%, Nov 2025 3.2%, Dec 2025 3.4%, Jan 2026 3.0%, Feb 2026 3.0%, Mar 2026 3.3%, Apr 2026 2.8%, May 2026 2.8%.
▸ Reported tool use: official.lookupmodel report
Read ONS May 2026 CPI component table and commentary for current-release pressure points.
↳ Fetched ONS component numbers: May 2026 CPI services annual rate 3.7%, CPI goods annual rate 2.0%, core CPI 2.6%, transport 6.8%, food and non-alcoholic beverages 2.2%, motor fuels 24.6%, petrol 157.4 pence per litre.
▸ Reported tool use: official.lookupmodel report
Opened ONS Consumer price inflation, UK: April 2026 to cross-check prior month dynamics and base effects.
↳ Fetched ONS April numbers: April 2026 CPI annual rate 2.8%, March 2026 CPI annual rate 3.3%, April 2026 CPI monthly rate 0.7%, April 2025 CPI monthly rate 1.2%, April 2026 CPI index 142.1, June 2025 CPI index 138.9.

Base rate/reference class: for one-month-ahead forecasts of this exact ONS CPI annual-rate series, the strongest base rate is persistence plus recent monthly changes. The latest three headline CPI annual rates were 3.3%, 2.8%, and 2.8%, averaging 2.97% if using March-May but 2.87% if downweighting March's pre-April energy-price-cap step. Since the June 2025 base month already had a 0.3% monthly CPI rise, June 2026 needs a monthly rise materially above 0.3% to push the annual rate above 2.9%.

Prior/update/interval: persistence prior is 2.8% from the latest ONS first-print headline, with a reference class of 12 successive monthly changes in the same CPI annual-rate series from May 2025 to May 2026: +0.2, +0.2, 0.0, 0.0, -0.2, -0.4, +0.2, -0.4, 0.0, +0.3, -0.5, 0.0 percentage points. The sample standard deviation of those changes is sigma = 0.27, so an 80% normal half-width is roughly 1.28*sigma = 0.35 percentage points. Level/index arithmetic: May 2026 CPI index 142.4 divided by June 2025 CPI index 138.9 gives 2.52% before June's monthly change; adding a plausible +0.3% to +0.4% June monthly move implies about 2.8% to 2.9%. I add one combined +0.1 percentage point current-pressure adjustment for services, transport, and possible fuel pass-through, giving a 2.9% point estimate; the 80% interval is symmetric before rounding and rounded outward to 2.5% to 3.3% for one-decimal first-print risk.

Current-release adjustment: the level effect from April's energy-price-cap fall has already entered the annual rate, while May's headline was unchanged at 2.8%. Transport and services are the main upside mechanism, but goods, food, and household-services easing keep the central forecast below 3.0% unless June air fares, fuel, or package holidays are unusually strong.

Counter-considerations: upside risk is a renewed fuel and air-fare jump after the Middle East shock, which would land above the interval if June monthly CPI exceeded about 0.75%. Downside risk is another broad goods and food disinflation month plus falling domestic energy or fuel prices, which would land below the interval if the June monthly CPI change was below about -0.05%. Outside the interval would most likely require a large transport-energy surprise or an unusually broad retail discounting month.

Review disposition: accepted the resolver critique by preserving the registered ledger URL/date/source wording in the JSON fields while documenting the apparent May/June inconsistency in reasoning; accepted the downside-tail wording fix; accepted the optional clarification that the +0.1 point adjustment is combined and that the interval is symmetric before outward rounding.

calibrated forecast · 80% CI
2.9%[2.5% · 3.3%]
Target metadata

Data point: ons.cpi.annual_rate.june_2026.first_print

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