Analysts suggest ONS seasonal adjustments inflate first-half UK GDP data, potentially revising 2026 Q1 growth 0.25ppt lower.
Recent UK GDP figures may exaggerate economic momentum due to flawed seasonal adjustments by the Office for National Statistics (ONS). A double-seasonal adjustment method indicates Q1 and Q2 growth could be overstated, while H2 figures may be underreported, skewing annual comparisons.
The ONS has defended its methodologies, but analysts note a recurring pattern of surging H1 growth and flat H2 performance since 2023. This distortion raises questions about the UK’s reported outperformance relative to G10 peers in early 2025 and 2026.
Adjustments suggest 2026 Q1 GDP could be 0.25 percentage points lower than reported, with later quarters potentially revised upward. The findings highlight concerns over data reliability amid ongoing scrutiny of ONS practices.