Retail mobile sites and apps are lagging behind their desktop counterparts, according to a survey by customer experience data firm Forsee.

The survey, which collected data from more than 460,000 consumer households, found a four point gap between retail websites (77) and mobile and apps (73) across the UK‘s top 10 mobile retail sites.

In the top ten, only Tesco had a higher ranked mobile website than its desktop version which points towards a mobile shortfall.

“It‘s important to remember that customers are using mobiles as a research medium too, to decide what products to buy from which retailers using which channels, so a less than satisfactory initial mobile experience also has the potential to drive buyers away from other channels like stores and call centres and into the arms of a competitor,” said Eric Feinberg, senior director of mobile at ForeSee.

Marks & Spencer, which is spending £2.4bn on areas such as logistics and IT over three years, joint topped the poll with Tesco. Grocer Ocado, which makes a third of its sales through its app, scored 73 respectively.

Perhaps the most surprising score was mobile-centred Shop Direct who scored 69. This month it predicted that every transaction via its sites will involve a mobile device from next year.

While shopping in-store, or ‘showrooming‘ more than two thirds (64 per cent) accessed retailers‘ website on their smartphone, almost a third (29 per cent) accessed a competitor‘s site and 17 per cent viewed a shopping comparison website.

Top 10 UK Retail Mobile Sites

Marks & Spencer – 75

Tesco – 75

NEXT – 74

Sports Direct – 74

N Brown – 73

Ocado – 73

Sainsbury‘s – 73

BrandAlley – 70

Currys – 70

Shop Direct – 69