The Ultra Low Emission Zone (ULEZ) is a measure aimed at improving the air quality in London. It operates 24/7, excluding Christmas Day (25 December), and covers all areas within the North and South Circular Roads. However, the North and South Circular roads (A406 and A205) are not included in the zone.

Most vehicles, including cars, motorcycles, vans, and specialist vehicles (up to 3.5 tonnes) and minibuses (up to 5 tonnes), must meet the ULEZ emissions standards or pay a daily charge of £12.50 to enter the zone. Residents of the Congestion Charge area are no longer eligible for the 100% discount on the daily ULEZ charge.

Lorries, vans, or specialist heavy vehicles (over 3.5 tonnes) and buses, minibuses, and coaches (over 5 tonnes) are not subject to the ULEZ charge, but they may still be required to pay the LEZ charge if they do not meet the LEZ emissions standards.