Hello, I'm Richard Lilwall, Chief Executive Officer at Quartix Technologies plc. Today I, along with our CFO, Emily Rees, will be presenting our interim results, plus an update on how we're executing on our strategic objectives and product launches. First, a very quick overview of Quartix Technologies. Quartix has been operating for over 20 years. During this time, we've grown from zero to being within sight of quarter of a million active subscriptions in our 24,000-strong customer base. Having started in the U.K., we've since achieved significant install bases in both France and the U.S., and have smaller but fast-growing subscription bases in other territories, most notably Spain, Italy, and Germany. The problem we solve for our customers is really about visibility. Once a mobile worker leaves base, the manager has no visibility of their workers.
Naturally, this can lead to waste that can be from workers not adhering to the daily plan, inefficient allocation of resources, and an inability to optimally plan future work. This lack of oversight has the potential for misuse of company vehicles, such as for personal mileage or even fraud via fuel or cargo theft. In the best case, this inefficient vehicle utilization will doubtless lead to significantly reduced capacity of the workforce with higher vehicle costs and more miles driven. Of course, our customers have a duty of care for their staff, and lone working, coupled with excessive and unnecessary miles, create significantly increased road risk. Finally, increased miles leads to much higher environmental costs. More miles means more carbon emission and more climate impact. How do we deal with these serious issues?
Our solution, in addition to a small hardware unit discreetly installed in the vehicle, is a simple-to-use cloud-based platform accessible in real time from any device. This platform gives managers new insights that empower instant improvements in their daily operations. High-risk activity can be identified and measured with countermeasures implemented to address this. 100% visibility of mobile workers increases accountability and reduces fraud risk. Additionally, the ability to allocate the right resource to the job, create better plans, and monitor adherence to plan greatly improve utilization and reduce cost. The ability to review and improve driving styles along with the reduced total road miles can offer really significant improvements in green credentials. I'll now hand over to Emily.
Thank you, Richard. I'm Emily Rees, CFO, and I would like to now take everyone through our summary of our interim results up to the 13th of June, 2022. Total revenue for the group was GBP 13.3 million, a 6.7% increase year-on-year. Just under 96% of revenue now comes from fleet revenue, and recurring revenues remained high at 92% of sales. Gross margin was 71.1% versus 69.1% in 2021. Quartix has not faced any major disruption due to component shortages year to date. Cost of sales for Quartix will always be adversely impacted in high periods of growth of new subscriptions due to its accounting policy, where the cost of new units and installations are recognized upfront.
However, in the same period, the mix of units sold to customers and the now diminished volumes of insurance business has still led to an overall improved margin for the business. Operating profit increased to GBP 2.4 million, a 17% increase year-on-year. Profit before tax for the period was also GBP 2.4 million. Adjusted EBITDA, which excludes share-based payment expenses, has declined 6.4%. Profit will be impacted by the pressure on cost of sales with the growth in new units as just mentioned, and also due to the annualization of the investment made into customer acquisition costs in the second half of 2021, both in terms of increased sales headcount and marketing costs.
Work continues on operational scalability, which allows our teams to improve customer satisfaction on our growing subscription base without adding further central headcount resources in 2022. Basic earnings per share were GBP 0.042 versus GBP 0.037 in 2021. On a diluted basis, earnings per share were GBP 0.0417. Overall cash generated from operations grew 5.5% year-on-year to GBP 1.9 million, which was just under 81% of the business's operating profit. With the strong results in the first half of 2022 and with new products and initiatives, including improved sales execution processes and operational scalability in the second half of 2022, we have confidence in achieving market expectations. Next, I will cover the business's main operational and strategic KPIs.
Quartix had 25.9% growth in new fleet subscriptions or units in the first half of 2022 versus 2021, at just over 32,000 new subscriptions. We are very pleased that our annualized recurring revenue, a forward-looking key performance measure, has returned to double-digit growth of 11.3% year on year to GBP 26 million on a constant currency basis. The subscription base has increased by 17.9% versus June 2021, with 221,800 units in the base and just over 24,400 customers, a 17.9% increase since June 2021. Our fleet attrition decreased year on year from 12.3% in the first half of 2021 to 11.6% in 2022, which reflects Quartix's continuing commitment to excellent levels of customer service.
Price erosion has also decreased year-over-year from 6.5% to 5.6%. The price erosion comes from the churn or renegotiation of contracts on the existing base rather than lower prices for new customers, which have remained constant for the past three years. The following slide shows the growth rates in the subscription base year-over-year. Each geographical market registered increases in both new subscriptions and in the subscription base for the period. The U.K. achieved new unit subscription growth of 23% year-over-year, and we are pleased to see double digit growth in the subscription base of our largest and most mature market of 11% year-over-year. New unit subscription growth was very impressive in France at 45.2% year-over-year.
This growth has been driven by return on investment from the expansion of our direct and field sales teams in 2021. France ended the period with 46,000 vehicles under subscription, a 31% increase year-on-year and just under 6,300 customers. The U.S. completed the first half of 2022 with a 16% increase in its subscription base year-on-year to approximately 30,000 vehicles and just over 4,000 customers. The growth rate in terms of new subscriptions in the U.S. is at a slower rate than we would have liked to achieve, which ended the period at an 8% increase versus the first half of 2021. In 2022, there have been challenges both in terms of retention of sales staff and also in customer retention.
We are currently undergoing further analysis into customer retention in the U.S. and believe we have the opportunity to improve ease of doing business with our U.S. customers, particularly around payment processes. We have new sales hires in place who will be contributing in the second half of the year. Our learning process about what works and doesn't work in the U.S. region continues, along with formulating the right commercial and operating model that will be scalable in the market. The rest of Europe continues to show excellent growth in the base of 88% year-on-year and with 30% growth in new subscriptions versus the first half of 2021, ending the period with just over 12,500 subscriptions across approximately 2,500 customers.
Strong growth is evident across Spain, Italy and Germany, and we believe these strong growth rates will continue due to the return on investment made in 2021 on the sales acquisition teams and marketing. Thank you. I'll now let Richard provide an update on Quartix's strategic objectives for 2022 and 2023.
Thanks, Emily. As we set out this year, we communicated our strategy would be based around three pillars. Next, I'll update on progress in each of these. Firstly, our push to drive excellence in sales execution. I described this as a multi-year project that will include best in class product demo and pitch, improved lead handling, scoring and grading, combined with nurture programs and best practice funnel management, allowing us to optimally match effort and spend to specific opportunities at all stages. Our plan here is very clear and investments have been made into some tools to help us achieve our goals. Implementation of the plan and tools has commenced, and we expect to complete the initial phase of this in the third quarter, with further refinements and optimization helping to drive further top line growth in 2023. Secondly, we set out to build operational scalability.
In this regard, we've sought opportunities for simplification, digital transformation and automation, ensuring we can offer our excellent levels of service to more customers without a corresponding increase in cost. I'm pleased to report our work on operational scalability has been successful so far, and we've made really strong progress. We identified and executed on a number of rapid improvements, meaning we've been able to serve our growing subscription base without adding any resources in 2022. Indeed, we've not just coped with this increase, we've also improved response times and increased customer satisfaction over this period. Naturally, there's always more to do, and the next phase we'll see is building a full end-to-end process map of our business to build an optimized model for today and for the future.
Thirdly, we wanted to ensure we deeply understand our customers by listening to them more closely than ever before, understanding their unmet needs, business challenges, and technology strategies. To this end, we launched our leadership customer adoption program with our whole leadership and top management team spending time with customers on an individual level with customer conversations and site visits. We've learned, I'm pleased to say, that we do a good job. They like the product and the people they deal with. It's fully backed up my initial impressions upon joining the business that our people care deeply about what we do and most importantly about our customers. They really recognize that it's the individual touch points with each customer that happen in their daily work that make all the difference.
We've also found there is more opportunity to help our customers further with some digital transformation initiatives, upselling of more functionality where they need it, and helping them to map their value steps and key performance indicators to our solution really effectively. At the start of the year, we also talked about some new products that we would be launching, and again, I'll update on these. First was the electric vehicle tool to help fleet operators understand how to transition their fleet from internal combustion engine vehicles to electric vehicles most effectively. The good news is that this is now launched, and it goes by the name of EVolve. We launched EVolve into the U.K. market in June and expect to be selling in France and in the U.S. in the very near future. We've seen really strong interest in the product from both existing customers and new prospects.
We have also had very positive feedback from our distribution and vehicle leasing partners. We have a healthy pipeline of opportunities, some generated from our launch webinar, which is available on our website. We've also made our first EVolve sale and are working to deploy that over the coming days. Overall, the early signs for EVolve are very positive. The second development was our Quartix Check app that helps drivers carry out their walkaround vehicle checks, ensuring their vehicle is safe to drive. The app allows managers to see in real time that checks have been carried out and can also see any issues or defects that have been logged about the vehicle.
We've completed our alpha testing on the app and are now moving through our beta testing phase with the aim of ensuring we're selling the app in all regions in the second half of this year, starting with the U.K. In summary, Quartix today is solving for fleet visibility and providing actionable insights to over 24,000 customers in seven global markets, and we have over 220,000 live subscriptions. Our subscription base has grown in line with our expectations at 17.9%. We've seen 25.9% more subscriptions sold in the first half than in the same period last year. Our low attrition rate of 11.6% continues, which, combined with our sales success, has driven annual recurring revenue growth of 11.3% and top-line growth of 6.7%.
On sales execution, we've made investments in tools, and we'll be implementing those through Q3. We'll see some impact in Q4 and anticipate full impact in 2023. In respect of our operational scalability, our rapid execution of fast-impacting initiatives has led us to improving customer satisfaction on a growing base while lowering costs. On product, we've launched and made sales of our EVolve EV transition tool, and we'll be launching Quartix Check across our regions over the second half. That concludes today's presentation, and I thank you all very much for listening.