The DWI (Drinking Water Inspectorate) says yes, all UK tap water is safe to drink. In blind taste tests, most people cannot tell the difference between chilled bottled water and chilled London tap water.
Sometimes London tap water can appear cloudy when you first fill a glass. Don't worry. This is just excess air which disappears in a few minutes.
The DWI recommends you drink the water from the cold tap as the hot tap may contain high levels of copper.
Find out more about where UK tap water comes from and why it's safe to drink.