London's ultra-low emission zone: what you need to know
How much it will cost, where it covers – and how to find out whether your car is liable
It comes into force on 8 April 2019, and will initially cover the existing congestion charge zone in central London, but will operate 24 hours a day, seven days a week. From 25 October 2021, it will expand to an area bounded by the north and south circular roads.
Source: Guardian Transport