A Which? survey of broadband speeds reveals that some providers are claiming speeds that are up to 62% higher than they really are.

The survey looked at more than 700,000 speed checks carried out in the first three months of this year and compared them with the speeds claimed by broadband providers. The survey worked with the median average speeds, calculated by ranking all the speeds in order and finding the middle one.

In 52% of the local authority areas checked median speeds were at least 10% slower than those claimed. And in 35% of areas speeds were at least 205%slower than claimed. Worst case was in Ashfield, Notts where the shortfall was 62%.

Which? are inviting broadband buyers to use their free speed checker service to determine if they are being seriously conned by their provider, and if they should be switching. And the survey has scored a win as the Advertising Standards Authority (ASA) will be implementing a new requirement for broadband providers to provide more accurate claims from May 2018.