Online grocery shopping is to have clearer price information, after consumers complained to the OFT.
The Office of Fair Trading said online users had cited differences in prices charged for groceries on delivery from those listed on supermarket websites.
The supermarkets claimed that the prices advertised are only guide prices relating to the prices of goods in-store at the time of ordering, while customers are often charged according to the in-store prices on the day of delivery.
Asda, Sainsbury, Tesco, Waitrose and its online partner Ocado, have now agreed to ease confusion by outlining their methods of pricing.
But the consumer watchdog is still advising customers shopping online to check prices at the point of delivery against guide prices listed at the time of ordering.