A major new study today reveals just how good Britain’s mobile phone coverage is – postcode by postcode.

The online study shows which areas get the fastest 3G signal and which are restricted to the slower 2G service. The latest smartphones, which offer internet and e-mail services, rely on a 3G signal to work properly. Phone companies say 90 per cent of Britain can get 3G.

But in many places people are relying on a 2G signal, which is around 10 times slower.

More than 44,000 volunteers took part in a three-week BBC survey of 3G coverage, providing testing firm Epitiro with some 1.7 million hours of data from around the UK.

The findings can now be seen on an online map, allowing people to type in their postcode to see the type of signal that is available in their area.

• To see the map click here

Gavin John, chief executive of Epitiro, said: “Over 44,000 volunteers from the Shetland Islands to the Isles of Scilly participated with 42 million locations tested from every county in England, Scotland, Wales and Northern Ireland.

“For the first time consumers have the means to see 3G coverage precisely where they live, work and travel.”

According to the map, the majority of Telford has 3G reception, but in some areas, including Ironbridge and Woodside, only the slower 2G signal is available.

Shrewsbury also has good 3G coverage with only a few areas, around Roman Road and Belle Vue Road, having the slower service.

In south Shropshire results are mixed, with Ludlow offering strong 3G coverage, but Craven Arms and Church Stretton relying on predominantly 2G services.

Mobile phone operators said they were broadly pleased by the survey. O2 said it “welcomed the crowd sourcing experiment”, but added that more detail – for example, signal quality – would have been useful.

A spokesman said: “The results don’t show the ‘experience’ on each network – for example, speed or the ability to hold a connection. Simply having coverage does not guarantee a good service.”

Everything Everywhere – the parent company of Orange and T-Mobile – said it “was a step in the right direction” for offering consumers transparent information about coverage.