Ofcom has launched a wi-fi checking tool to improve broadband as it emerged that six million UK premises could be receiving a better service, with small-to-medium enterprises (SMEs) particularly poorly served.

The Connected Nations 2015 report found that 27 percent of homes now have (by Ofcom’s definition) ‘superfast’ broadband of 30 Mbps or more, representing an increase from 21 percent a year before.

It was also found that superfast broadband is available to 83 percent of UK homes, up from 75 percent last year.

However, there were some notable patches revealed. The report found that only 68 percent of SMEs have access to superfast broadband compared to 85 percent of all premises. 400,000 SMEs have no superfast broadband. In addition, 130,000 SMEs in certain business areas are unable to receive speeds above 10 Mbps.

"As at August 2015, only 46 percent of premises in SME-only postcodes (e.g. business parks) had broadband connection speeds at a maximum of 10Mbps and 12 percent had less than 2 percent," said Kester Mann, Principal Analyst at CCS Insight.

"This suggests that residential roll-out has received higher priority and that SMEs may have been over-looked."

This weak spot in the national infrastructure could be explained by the high capital expenditure required to install broadband connectivity. Schemes like the Broadband Connection Voucher Scheme, which was discontinued in October, targeted this problem by providing public support for such installations.

Rural areas were also still significantly behind urban areas, although the gap was narrowing. Availability of superfast broadband to rural areas reached 37 percent of premises in this report, an increase from 22 percent in 20154.

Mann said this was an "encouraging jump" but "will continue to fuel concerns of a digital divide in the UK."

These areas of poor coverage look like a missed opportunity, as the report saw that the amount of data used by those with faster connections increased dramatically.

While broadband households with speeds under 40 Mbps used a maximum of around 110GB per month, at this threshold some households’ usage increased to over 140GB per month.

"For the first time, Ofcom pointed to evidence that users with speeds above 40 Mbps are downloading significantly more data. This suggests faster speeds and better quality networks drive usage of new services and behaviour. This could give weight to the argument that the UK’s weak position on ultrafast broadband is a concern."

As part of an attempt to improve broadband, the regulator launched the free Ofcom Wi-Fi Checker app, which runs on smartphones and tablets and allows users to assess the strength of their connection.