A sixth of the UK is made up of mobile commerce blackspots, with consumers either unable or unwilling to conduct transactions on the go, according to research.

The areas in question include a mix of predictable areas such as the Outer Hebrides and rural Wales and surprising areas like parts of central London.

EBay commissioned market research firm Verdict to question 1,500 adults across the UK, with the research leading to the firm predicting that mobile shopping could deliver a £4.5 billion boost to Britain’s economy by 2016, and a further £13bn by 2021.

Ebay said "m-commerce" is on the verge of a potential four-fold increase over the next five years as consumers become more comfortable with shopping on their handsets.

But it warned that the market is currently being held back by "unreliable" mobile broadband. EBay says UK retailers are missing out on at least £1.3bn as a result of consumer frustrations with patchy coverage, unreliable connections and slow connection speeds.

It says the research shows that 16 percent of the UK is an “m-commerce not-spot”, where mobile spending is at least 20 percent below the national average.

More than a third of consumers have failed to complete a purchase on their mobile due to "issues" with mobile broadband.

Although network coverage (79 percent), the reliability (85 percent) and speed (86 percent) of mobile internet connections rank highly as barriers to mobile shopping, consumers are also heavily put off by the cost of data (80 percent).

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When asked their views on what should be the top priority for mobile networks and regulators, the cost of data came out top (over half), with improving coverage in second place (23 percent). One in ten think improving the reliability of internet connections in urban areas (14 percent) should be the priority, followed by providing better internet coverage on transport routes (13 percent).

Angus McCarey, eBay UK retail director, said: “Mobile shopping represents a massive opportunity not just for retailers, but for the economy as a whole. But our research shows that consumers and retailers are missing out as the cost and reliability of mobile broadband prevents shoppers from spending."

The areas with the least m-commerce included the Outer Hebrides, with the lowest spending, followed by the likes of Llandrindod Wells in Wales, Perth in Scotland, Isle of Man, Jersey, and parts of central London with the WC postcode - which includes "trendy" portions of Islington, Clerkenwell and Farringdon.  

The areas with the higest m-commerce spending were led by Birmingham, and also included Chester, Leeds, and Halifax. Only Romford in Essex squeezed into the top five from the south.

In the US, Google recently launched a mobile wallet platform that will let people with special phones pay for goods in retail shops by tapping the phones against a payment terminal.

The Google Wallet initially supports US users with Mastercard credit cards from Citi, and users can pay for goods at 120,000 major stores. Telecoms operator Sprint is also a partner, since it sells Google's Nexus S phone, one of the only phones in the US capable of using the new Google Wallet.