First London TX4 black cab upgraded to Euro 6 as TfL approves retrofit breakthrough
- Perry Richardson
- Apr 15
- 2 min read
The first London TX4 taxi has been successfully upgraded from Euro 5 to Euro 6 emissions standards following approval from Transport for London (TfL), marking a significant development for the capital’s taxi fleet.
The retrofit, delivered by HJS Emission Technology, enables older diesel black cabs to meet the equivalent of Euro 6 requirements. The upgrade allows vehicles to remain licensed for up to 15 years, aligning them with the operational lifespan permitted for newer compliant taxis.
London-based driver Bobby Holley became the first to complete the TfL-approved conversion. Following inspection and certification, his vehicle licence was renewed, providing a route to continued operation that had previously been uncertain for many drivers.
Holley described the approval as a key moment for the trade, stating: “This is what we’ve all been waiting for. There was a point where it felt like it might never happen. Now drivers like myself have a clear way forward and can finally plan for the future.”
Milestone approval offers black cab drivers a compliant alternative to full vehicle replacement amid tightening emissions rules
Thousands of TX4 owners have faced mounting pressure from tightening emissions regulations, age limits and the high upfront costs associated with transitioning to zero-emission capable vehicles. The retrofit offers a lower-cost compliance pathway, potentially extending asset life and reducing immediate capital expenditure.
HJS said the system had undergone extensive development and investment to meet regulatory standards required by TfL. The approval effectively unlocks a programme that has been anticipated by drivers seeking alternatives to full fleet replacement.
From a market perspective, the retrofit solution may ease short-term supply pressures within the licensed taxi sector. By allowing more vehicles to remain in service, it could help stabilise fleet numbers while the transition to electric taxis continues at a slower pace than initially projected.
The technology is also viewed by some drivers as an interim measure that supports environmental targets without forcing rapid and potentially disruptive change. While not zero-emission, Euro 6 compliance significantly reduces harmful pollutants compared with older diesel standards, contributing to improved urban air quality.
HJS indicated it is preparing to scale the rollout across the capital, with further upgrades expected as demand builds. The company positioned the retrofit as a bridging solution, allowing drivers to maintain earnings while planning longer-term investment in zero-emission capable vehicles.
Holley added: “It’s a relief to finally have my cab compliant to Euro 6. I am glad I decided to be the first to adopt this technology, and after my cab passed its licensing inspection today, I am looking forward to another three years in my TX4."
