This is a list of supermarket chains in the United Kingdom. Grocery sales in the UK are dominated by Tesco, Asda, Sainsbury's and Morrisons. These, dubbed the "big four", had a combined market share of 73.2% of the UK grocery market in the 12 weeks ending 4 January 2015, a decline from 74.1% in 2007. Discounters Aldi and Lidl have seen a combined rise in market share from 4.8% to 8.3% over that time, while upscale grocer Waitrose's share rose from 3.9% to 5.1%. As of Kantar data published on 5 March 2021, the market share is dominated by Tesco, with Sainsbury's being second, Asda third and Morrisons fourth.