What will the completion of the major deal mean for you?
Millions of UK customers for Vodafone and Three are being promised “huge improvements” in their mobile coverage following the seismic merger of the two mobile operators.
A summary of key findings drawn from SignalTracker’s data
Background
VodafoneThree is now the UK’s largest network, the country’s third and fourth largest mobile networks completing the long-awaited deal on May 31. The new conglomerate promised that 27 million customers will begin to experience benefits for their signal coverage and quality.
Though initial announcements by Vodafone gave the impression that 27 million customers will “start to benefit from unrivalled access to roam across each other’s networks” within months, this is not the full picture. [1]
New details released last week show that the system will work using a network sharing system called “multi-operator core network” (MOCN) [2]
For users, this will mean that if your phone has a Vodafone or a Three SIM, it will connect to either a Vodafone or Three mast depending on the best signal in your location. The full rollout of this is expected to take 8 years total. Vodafone have emphasised that the system will be 95% complete after six years.
Limitations and a years-long rollout
Both 4G and 5G non-standalone services – which rely on pre-existing 4G infrastructure will benefit but users of 5G standalone services such as Vodafone’s 5G Ultra will not. They will have to wait longer as the operator claims the system cannot support them. The only detail from Vodafone on this is that it is “planned for the future”.
5G standalone is faster and has improved latency compared to the 4G dependent non-standalone service and this means that Three customers will likely not benefit from the sharing of Vodafone’s advanced 5G infrastructure for a long time.
Companies piggybacking off Three and Vodafone’s network infrastructure (MVNOS) such as Voxi and Smarty will also see their customers treated in the same way – their sims automatically connecting to the best mast near their customers.
In our tests, we have averaged the speed for both Vodafone and Three individually and then taken an average with their respective MVNOs – Talkmobile and Lebara for Vodafone and ID and Smarty for Three.
Companies such as ID will need to negotiate on how their customers will benefit, as they use Three’s infrastructure but won’t be automatically using the best mast.
VodafoneThree claim “investment will boost speeds for every customer as we bring 5G standalone to every corner of the UK by 2034.” A key part of this promise is that coverage will extend wholesale from busy city centres to remote rural towns.
As of June 2025, the mast switching MOCN technology has been enabled at 24 masts across the UK. By March 2026, 10,000 more sites will have the technology though it is unsure where the current masts are located.
Three Customers have the most to gain
We have compared data obtained through the SignalTracker App, which helps determine the quality of network coverage in the UK, to try and understand the true benefit the Vodafone/Three merger could have for customers.
What about speed and access to 5G non-standalone? Our UK wide results for 5G non-standalone, which will be shared between Vodafone and Three customers, show that the average download speed on Vodafone is 71.04 Mbps and only 45.05 Mbps on Three for that generation.
Speed and reliability seem to be the biggest upgrades for Three customers but Vodafone customers benefit by having sole access to 5G standalone – the absence of this for Three users is disappointing.
Graphs comparing signal strength and network coverage for Three and Vodafone in central London
The situation in London
To focus on just London for a speed comparison, as it is the most developed location in the UK for the 5G non-standalone rollout, Three customers get 30.82 Mbps download speeds on average when connected to non-standalone 5G.
Compare this to Vodafone customers who currently get 45.99 Mbps download speeds on average throughout the entire city. Both fall short considerably of the promised 100 mbps maximum that Vodafone touts but once again, Three customers have the potential to gain from a system which connect them to faster and better masts.
Adding in our MVNOs improves the download speed averages but Vodafone remains ahead. Vodafone and its MVNOs average to 52.6 Mbps and Three averages to 31.77 Mbps.
For some additional context on the impact that 5G Standalone has on our figures – Vodafone 5G Ultra has an average download speed of 95.18 Mbps, crushing the speed of a Three non-standalone device.
In our testing in London, with a Vodafone device, 37% of the time it was getting a 5G non-standalone signal and with a Three device, it was actually higher at 54%.
This suggests that should the rollout progress smoothly, there could be an improvement as well in coverage for Vodafone customers, though the speed of Three’s network poses questions about the equality of that deal.
What about 4G download speeds?
Taking a mean average of London’s 4G, as another case study, our data shows Three on 25.57 mbps with Vodafone customers on 37.16 Mbps. The difference is not substantial but once more demonstrates the speed and maturity of Vodafone’s network.
Bringing MVNOs into the calculation does close the gap but Vodafone still wins out for download speed. Vodafone and its associated networks average 28.12 MBps and Three manages 24.82 MBps, clearly this draws things closer but not enough.
Broaden this scope to the entire UK and we meet with a similar conclusion. In 4G tests, Vodafone trounces Three with a 37.86 Mbps download speed average as opposed to Three’s 29.39 Mbps count.
Currently Vodafone is part of a sweeping project – the Shared Rural Network Programme – in an aim to cover signal not-spots across the UK with 4G. However the MOCN technology will not be part of this project.
References
[1] – https://www.vodafone.co.uk/help-and-information/vodafone-three-merger-questions
[2] – https://www.vodafone.co.uk/newscentre/features/merger-sharing-mobile-networks-everything-you-need-to-know-mocn/
