FX.co ★ UK RPI Inflation Almost Stalls in September, Slowing Sharply to 0.1% MoM

Retail Price Index (RPI) inflation in the United Kingdom slowed markedly in September 2026, with the month‑on‑month rate easing to 0.1%, down from 0.6% recorded in August 2026. The fresh data, updated on 21 October 2026, highlight a sharp deceleration in price growth compared with the previous month.

On a month‑over‑month basis, the latest reading shows that prices barely increased in September compared with August, whereas August had seen a more pronounced rise versus July. According to the comparison framework, the “actual” September figure reflects the change versus August, while the “previous” August indicator captures the change from July, underscoring how quickly inflationary momentum in RPI has cooled heading into the autumn.