RaoscaffResearch
Prediction Series · Lock · Issue P-146
Prediction Series · P-146

The UK ceiling — ≤3.5%, locked at 92%.

92% probability UK headline CPI rises at or below 3.5% in the twelve months to September 2026 — a ceiling set 0.9pt above the 2.6% June print. Resolves ~21 Oct 2026.

Type · Prediction Lock · inflation ceiling Locked · 2026-08-13 · before the September release Resolves · ~2026-10-21 · ONS Consumer price inflation, UK (ons.gov.uk) Scored · binary: September 2026 headline CPI ≤3.5% YoY yes/no
UK September 2026 headline CPI · our locked ceiling
≤ 3.5%
annual CPI · vs 2.6% in the twelve months to June 2026

ONS reported UK headline CPI rising 2.6% in the twelve months to June 2026, published 22 July 2026. Our ceiling sits 0.9pt above that reading. Source: ONS, Consumer price inflation, UK.

— 1 · The Locked Call

UK September 2026 headline CPI lands ≤3.5% YoY — P = 0.92.

We lock a binary: UK headline CPI for September 2026 rises at or below 3.5% year-on-year, per the Office for National Statistics. Confidence 92%.

— 2 · Why it's nail-able

The ceiling sits nearly a full point above the latest verified print.

UK headline CPI stood at 2.6% in the twelve months to June 2026, leaving 0.9pt of headroom to our ceiling over a three-month horizon. Confidence 92%, not higher, because two further monthly prints — July, released 19 August, and August — land before the scored September figure, and services inflation has been the persistent upside risk. Scored on the first-published ONS headline CPI rate for September 2026.

Locked on 2026-08-13 — scored against the ONS September 2026 CPI release.

RAOSCAFF locks P-146 on 2026-08-13, before the September release. Scored against the UK September 2026 headline CPI annual rate versus a 3.5% ceiling.

Locked
2026-08-13 (commit timestamp on origin/main)
Resolves
~2026-10-21 — ONS Consumer price inflation bulletin for September 2026
Source
Office for National Statistics, Consumer price inflation, UK — headline CPI 12-month rate (ons.gov.uk)
Scored by
Binary: YES if the September 2026 UK headline CPI 12-month rate is ≤3.5%; NO otherwise. Headline CPI, not CPIH and not core.

Services inflation is the persistent upside risk; two monthly prints land before the scored figure.