Cars need to meet minimum emission standards when travelling in the Ultra Low Emission Zone (ULEZ) or the daily charge must be paid.

Minimum emission standards

Petrol: Euro 4
Diesel: Euro 6

The ULEZ will be enforced based on the declared emissions of the vehicle rather than the age. However:

• Petrol cars that meet the ULEZ standards are generally those registered with the DVLA after 2005, although cars that meet the standards have been available since 2001
• Diesel cars that meet the standards are generally those registered with the DVLA after September 2015

Information from Transport For London

Check this car on the TFL website before purchasing: https://tfl.gov.uk/modes/driving/check-your-vehicle/