Recent data shows that the UK’s mobile networks are falling behind: Opensignal ranks the UK just 54th globally for network excellence, with consistency and reliability particular weak points. Customer surveys show poor network quality is a leading reason people switch providers, while operators say squeezed returns have made it hard to invest enough to maintain quality and keep up traffic growth.

Against that backdrop, it is hoped that the merger between Vodafone UK and Three UK, approved by the Competition and Markets Authority (CMA) with binding investment commitments, will give mobile infrastructure in the UK a much-needed boost. Early Opensignal reports already show tangible improvements: post-merger users of the merged networks are seeing wider coverage, better reliability and faster speeds.

On 6 November, Frontier Economics hosted an IIC UK Chapter Meeting on the Future of the UK Mobile Sector, which reflected on the big investment challenges that lie ahead. Frontier Economics’ Martin Duckworth moderated the session and he was joined by Brian Potterill (Policy Director, Ofcom), Ceri Howes (VP of Government and External Affairs, Opensignal), Ian Corden (CEO & Founder, Peira Consulting Limited), and Jobanputra Shamil (BT Group Regulatory Affairs). The session sparked a lively discussion, covering a broad spectrum of issues facing the sector.

Here are some of the key themes that emerged.

The need to addressing gaps in rural coverage

Despite recent progress with the UK Government’s Shared Rural Network (SRN) initiative, sizable gaps remain in rural mobile coverage. While over 99% of the UK population is now covered by a 4G signal, large parts of the country - particularly in Scotland, Wales, and parts of northern England - still suffer from partial or total “not spots”. The combination of high deployment costs, local planning opposition, and weak investment incentives makes universal, high-quality mobile connectivity one of the most difficult challenges for UK infrastructure. Filling the final gaps will likely require a mix of existing and novel technologies (like D2D satellite), deployed with a combination of private and public funding; and close coordination between MNOs, Ofcom and government.

The potential for direct-to-device (D2D) satellite

Recently, there has been much interest around “Direct to Device” (D2D) technology as a potential solution to coverage challenges in very rural areas. D2D allows standard smartphones to connect directly to satellites for connectivity, without needing extra hardware. Whilst D2D is highly promising, it is yet to be deployed at scale, and a combination of capacity limitations, cost, and integration hurdles mean that initially it will likely be complementary to (rather than a substitute for) conventional terrestrial deployment. D2D appears ideally suited for filling the last few percent of rural and remote coverage gaps, enhancing resilience, and supporting emergency communications.

The importance of reducing planning barriers

Planning continues to be a major barrier for network deployment. Operators must navigate a patchwork of over 300 local authorities, each with their own systems and approach. In many cases local objections can result in outright refusal for permission to deploy new sites, which means persistent gaps in coverage or poor quality. 

Recent measures, such as the expansion of permitted development rights and restrictions on landlords ability to charge excessive rents, have been welcomed. However, operators argue much more is needed, including streamlining approvals, increasing permitted mast heights, and better harmonised decision-making.

How to improve coverage on the railways

Using a phone on the train in the UK can be a frustrating experience. The rail network presents major technical challenges: trains’ metal bodies block radio signals, and routes often run through tunnels, deep cuttings, and remote areas with few cell sites. With limited commercial incentive for operators to invest heavily in dedicated rail coverage, meaningful improvement will likely require a coordinated national effort, supported by public funding. Switzerland offers one model—treating continuous rail coverage as a national infrastructure priority has enabled it to achieve near-universal 4G connectivity across its network.

Future spectrum needs

Spectrum, together with sites, is a key building block for mobile network quality and capacity. Low-band frequencies (< 1 GHz) are in especially high demand because they deliver wide, reliable coverage—but supply is tight, and these bands often become congested first. Looking ahead, the 600 MHz band seems the most promising new source of low-band spectrum for mobile use in the UK, but requires digital terrestrial TV services to be reconfigured or ceased. Additional mid-band capacity could also come from making more of the 3.8–4.2 GHz range available to national mobile networks, and potentially from future allocations in the 6 GHz band. However, progress is constrained by competing demands from defence, and other spectrum users, as well as the slow pace of reallocation and clearance. For policymakers, the challenge is to strike a balance between protecting existing services and enabling timely access to spectrum needed to sustain investment and improve coverage.

Strengthening resilience

Connectivity underpins essential services, emergency response, and economic activity. Due to this, network resilience has become  increasingly important for the UK mobile market.  Recent incidents, including storm damage, power outages, and cyberattacks, have highlighted the vulnerability of mobile networks to both physical and digital disruptions. As with rural coverage and coverage on railways, investment in resilience offers little short-term commercial return, making it hard for operators to justify commercially. Resilience also requires coordination with the energy sector improving grid reliability, prioritising power restoration for critical communications sites, and supporting the rollout of local energy storage could all bolster network stability. Achieving greater resilience will require a mix of strategies including investment in shared infrastructure as well as targeted government subsidy and close coordination between mobile operators and  energy providers.

Conclusion

The UK mobile market is entering a new phase – the VodafoneThree merger should help close the UK’s investment gap with its peers, but deep-seated challenges remain. Long-term success will depend on joined-up policymaking that recognises mobile connectivity as a vital national infrastructure.