Only diesel vehicles meeting the Euro 5 standard are allowed to circulate.

From 1 January 2022, diesel cars with Euro standard 4 (or lower) are no longer allowed to enter the LEZ. If they do so they have to pay a fine of 350 euros. 
However, a transition period has again been provided, during which offenders will receive a warning. 
For more information on where to buy stickers go here.

Source: Pixabay