Set ddata Consumer price inflation detailed briefing note

05 June 2025

An error has been identified in an extract of the licensed vehicles data provided to the Office for National Statistics (ONS) by the Department for Transport (DfT), which is used to calculate the April 2025 Vehicle Excise Duty (VED) component of consumer prices inflation. The incorrect data overstate the number of vehicles subject to VED rates applicable in the first year of registration.

This has the effect of overstating the headline Consumer Prices Index including owner occupiers’ housing costs (CPIH), the Consumer Prices Index (CPI), and Retail Prices Index (RPI) annual rate of change by 0.1 percentage points for the published April 2025 figure only. No other periods are affected. In line with our consumer prices revisions policy, these statistics will not be amended.

The ONS will be using the correctly weighted data from May 2025’s figures onwards. The DfT’s published official statistics are unaffected.

This error is isolated to one component dataset that is used to calculate the VED index. However, the ONS is reviewing its quality assurance processes for external data sources in light of this issue.

Please see the table Impact of vehicle excise duty error on headline UK consumer inflation, April 2025 for more detail.