Please note: Converting to gas or installing a filter does not guarantee your vehicle will meet the ULEZ standards or the revised LEZ standards effective from 25 October 2020 for vehicles over 3.5 tonnes.
You can choose to convert your vehicle to run on pure gas with a spark ignition, using an approved conversion.
If your vehicle is registered in Great Britain, you'll need to register the conversion with the DVLA and obtain a certificate from the Driver and Vehicle Standards Agency (DVSA), formerly VOSA. Please be aware that vehicles converted to run on bio-diesel don't meet the required emissions standards.
The ULEZ and LEZ schemes allow for some vehicles to retrofit emissions reduction technology to meet the standards.
Retrofit technologies need to be certified by the government's Clean Vehicle Retrofit Accreditation Scheme (CVRAS). The CVRAS currently has emissions reduction technologies certified for buses, coaches and refuse vehicles. We expect retrofit technologies to be developed for other specialist heavy vehicles where replacing the vehicle would be very expensive.
Any HGV, bus, coach or refuse vehicle with emissions reduction technology fitted must have this certified by the CVRAS. Once certified, the owner should notify TfL directly.
More details on the retrofit accreditation process and suppliers are available on the CVRAS website.
You could upgrade to a newer vehicle that meets the standards or an electric vehicle, or you could convert to gas using an approved conversion.
If you operate a fleet of vehicles, you could reorganise it so that only vehicles meeting the emissions standards are driven within the zone.
We would prefer that your vehicle meets LEZ standards. However, if you're not able to take the measures needed, then you can pay the daily charge to drive within the zone.