For the first time ever, the smartphone has overtaken desktop's share of online sales in the UK, making it the dominant device for shoppers buying online.
Over 40% of online sales were made using smartphones in the fourth quarter of 2018/2019, according to the latest Capgemini IMRG eRetail quarterly sales index which is compiled using data from 210 UK retailers.
The report describes the findings as a "major milestone" as shoppers spent more money through their smartphones when accessing UK retail sites than either of the other two other main device types - desktop or tablet.
In Q4 2018/19, which covers the Christmas retail quarter of November, December and January, the share of sales revenue spent through smartphone devices was 40.4%, with desktop securing 39.7% and tablet 19.9%. A further milestone was reached in December 2018, when smartphones accounted for over 70% of mobile device sales for the first time (the other 30% was spent through tablets).
UK shoppers are also increasingly using mobile devices for accessing retail sites. In Q4, 74% of retail website visits were made through mobile devices, with just 26% made through desktops. Back in 2015, the percentage of visits coming through smartphones and tablets versus desktops was even.
"This is another significant step in smartphones becoming the dominant device through which we manage so many aspects of our lives," said Andy Mulcahy, strategy and insight director at IMRG.
"It has taken a little while though - the iPhone was first released in 2007, and for a long time people were visiting product pages through smartphones in large numbers but then completing purchases elsewhere. It wasn't until late 2015 when it started to really gain traction as a fully transactional device for online shopping.
"This does not spell the end of other devices being used for online retail purchases, however - people tend to use multiple devices depending on which is most convenient. So, for example, during standard working hours a higher proportion of sales come through desktop as people are sat in front of their computers at work."
Lucy Gibbs, senior consultant in retail analytics at Capgemini Invent, said: "Smartphones make it is easier than other forms to be truly omni-channel, which is about being where your customers are, and therefore are optimally placed for influencing the retail customer journey. The advancements over the last few years in mobile banking, in app purchases and a greater focus on optimising m-commerce sites have all led to the facilitation and increased confidence in purchasing on smartphones.
"Although smartphones have now reached largest share in revenue, they are still seeing the lowest conversion rates, behind tablets and desktop. However, the significance of our use of mobile in influencing our buying decisions should not be underestimated even when we are completing purchases elsewhere."
Written by Rachel Miller.