We’re proud to announce the first successful, TfL-approved upgrade of a TX4 taxi from Euro 5 to Euro 6 emissions standards.
London taxi driver Bobby Holley is the first in the capital to complete the upgrade using HJS emission reduction technology. As a result, his vehicle now meets Euro 6 equivalent standards, allowing it to remain licensed for up to 15 years—in line with newer Euro 6 taxis.
Following successful TfL inspections, Bobby’s licence (plate) has now been renewed, marking a huge moment for both him and the wider trade. Holley described the moment as a turning point after years of uncertainty across the trade:
“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.”
This achievement represents a significant breakthrough for thousands of TX4 owners looking for a practical and cost-effective route to compliance, without the immediate need to transition to an electric vehicle.
The TfL approved retrofit programme provides a vital solution for drivers facing tightened age limits and rising vehicle costs. By extending the working life of existing taxis, the HJS system offers a financially viable alternative that supports drivers while maintaining London’s commitment to improved air quality.
After extensive investment and development, HJS has delivered a fully certified solution, unlocking a programme long anticipated by the industry.
This retrofit technology is widely seen as a critical bridge, enabling drivers to continue operating their current vehicles while preparing for a gradual shift toward zero-emission capable taxis. It also helps stabilise the market by reducing immediate financial pressure and supporting long-term sustainability.
For Holley, the benefits are clear:
“It’s a relief to finally have my cab compliant to Euro 6. I’m glad I made the decision to be first, and after passing the licensing inspection, I’m looking forward to another three years in my TX4.”
With the first successful upgrade now complete, HJS look forward to supporting more drivers across London as the rollout gathers pace—delivering a proven, compliant, and driver-focused solution for the future of the black cab industry.
