Online retail sales in the United Kingdom increased 16% in March compared with the same month a year earlier, according to the latest report from business and technology consultancy Capgemini and U.K. e-retail association Interactive Media in Retail Group.

For the first quarter of 2013, e-commerce sales increased 15% compared with the same period in 2012, the two groups say without giving spending figures.

Online apparel sales were particularly strong in March, with 15% growth year over year, the report says. The report gave no growth figures for other product categories.

The two groups did say, however, that sales stemming from smartphones and tablets increased 243% year over year in March. The average m-commerce conversion rate in March declined to 1.8% from 2.3% in February.

 “As retailers continue to develop multichannel offerings and improve mobile services in line with an ever-evolving technology, the high street will struggle to match the performance of their online counterparts,” says Chris Webster, Capgemini’s vice president, head of retail consulting and technology; “high street” is the British term for main street.