The ULEZ, or Ultra-Low Emissions Zone, is an area of London within the North and South Circular Roads where older and more polluting cars face a £12.50 daily surcharge to enter. From August 2023, this will expand to cover the whole of Greater London.
Petrol cars will not have to pay the surcharge if they meet Euro 4 emissions standards or better – generally speaking, this includes most post-2005 petrol cars. For diesels wishing to avoid the charge, they must meet the latest Euro 6 standards introduced in 2015.
Note, that these costs are separate and in addition to the congestion charge, which all non-EVs must pay to enter Central London.