Excluding London, prices rose even higher – by 4.4%.
The overall 4% figure is the biggest change across a year since 2016, which is when the ONS began this data series, it reports.
Prices in England went up by 3.9% over the year, by 3.1% in Wales, and by 4.4% in Scotland.
The biggest rise could be found in the East Midlands, which posted an increase of 5.1% while London and the North East both saw the lowest annual growth, at 3.5%.
The ONS adds that while London saw the lowest growth, its 3.5% figure is still the biggest annual percentage change recorded for the capital since April 2016.
ID-Pal chief executive Colum Lyons says: “It’s a turbulent time for landlords and tenants.
“Increases in interest rates on mortgage payments, which have more than doubled in the last six months, are in turn pushing up rental prices.
“A lack of supply is further spiking demand for competitively priced properties, meaning letting agents’ and landlords’ have to react quickly.”
