Food prices provided the biggest downward drag on the headline rate, the ONS said, while motor fuels pushed it higher.
The core figure, excluding energy, food, alcohol and tobacco, came in at 4.2%, compared with a projection of 4.1%.
Services inflation, a key watcher for U.K. monetary policymakers, declined from 6.1% to 6% — again above the expectations of both economists and the BOE.
This week, investors have been monitoring signs of a cooling U.K. labor market, with unemployment unexpectedly rising to 4.2% in the period between December and February.
The central bank's own forecast is for inflation to "briefly drop" to its 2% target in the spring before increasing slightly.
Persons:
BOE, BOE Governor Andrew Bailey
Organizations:
National Statistics, Bank of England, Reuters, Federal Reserve
Locations:
U.S