The first Clean Air Zone (CAZ) in the UK to include private vehicles is being implemented by Birmingham City Council from 1st June 2021. This follows the city of Bath’s CAZ which came into effect on March 16.

Birmingham Clean Air Zone will be a Class D CAZ meaning all non-compliant, non-exempt vehicles face a daily charge for coming into the city centre

https://www.birminghammail.co.uk/all-about/clean-air-zone