UK retail ecommerce sales are set to exceed £67 billion in 2016, fueled by some impressive growth in smartphone-based buying, according to eMarketer’s latest forecast. The UK is a world leader in terms of retail ecommerce’s share of total retail sales, and by 2020 digital retail sales will represent a 22.6% share.

The growing retail ecommerce market is helping to offset a decline in traditional retail sales in the UK. The total retail sector, which includes high-street shopping , suffered negative growth last year, but it is set to start rebounding in 2017 when it will grow by 0.9% to reach £404.75 billion.

UK consumers have always been quick to embrace digital technologies and eMarketer’s forecast shows that this extends to shopping and buying. In particular, they are easily making the shift to spending on mobile devices. In 2016, total mcommerce sales will account for £25.2 billion, an increase of more than 25% on the previous year. UK retail mcommerce sales will continue to exhibit double-digit growth throughout the forecast period, and by 2020 mcommerce sales are expected to exceed £42.5 billion.

The majority of mcommerce sales currently comes from tablet devices—this year, £15.8 billion will be spent via tablets, representing more than 62% of total mcommerce sales. However, smartphone shopping is fast gaining ground. It currently accounts for just 36.4% of mcommerce spending, but by 2020 the balance will have tipped and it will account for 52.0%, and sales of £22.1 billion.

“Smartphone usage continues to have far-reaching implications for retailers in the UK,” said Bill Fisher, senior analyst at eMarketer. “However, more than simply driving digital retail traffic, these latest numbers show that smartphones are now increasingly driving digital sales. Getting the smartphone sales experience right is becoming more vital than ever. ”