Outdated technology is affecting retailers' websites, according to analyst Ovum.
A buoyant online retail market has driven many businesses to set up websites. But increased demand is overwhelming retailers' platforms, said analyst Christine Bardwell.
"Now we are in the second wave of e-commerce and lots of companies are in a position where they need to improve the user experience of their websites," she said.
Retailers have been quick to respond to consumer demands for online shopping, added Christine Bardwell. "Zara and H&M are the only two retailers I can think of who do not currently have [transactional] websites," she said.
Bardwell's comments followed retailer Accessorize's online debut. The accessories and clothing firm's website had previously been incorporated in parent company Monsoon. The company plans to make the online store available in German, French and Danish.
According to Monsoon and Accessorize chief commercial officer, Steve Back, the company intended to create an online experience similar to walking into an Accessorize store.
"The return on investment from the online opportunity is sizeable," he added.
E-commerce sales in June rose a fifth year-on-year, according to a study from industry body IMRG. Online shoppers spent a total of £4.4bn during the month.
This was the second consecutive month that year-on-year growth has been above 20 per cent. It was the highest rate since June 2008, the report added.