The combined value of UK’s top 13 brands has dropped by 4% over the past year, according to the latest data from Kantar Millward Brown’s BrandZ.

Vodafone, which tops the UK ranking, has seen a 14% drop in brand value to $31.6bn. BT has seen a similar fall in its value, meaning it drops back into fourth place with a valuation of $16bn.

BT has had a tough few months, after an accounting scandal in Italy wiped £8bn off the stock market value of the company, while the quality of the BT OpenReach service was called into question in Ofcom’s Digital Communications Review (DCR) in 2016.

“This has eroded trust in our brand. When it comes to the…