Biggest UK mobile groups suffer worst year of customer losses
Incumbents are increasingly ceding ground to virtual rivals who pay to access their network
The UK’s biggest mobile operators experienced their worst year of customer losses on record in 2025, as established operators lost ground to cheap insurgent rivals.
BT, Virgin Media O2 and VodafoneThree lost a combined 972,000 mobile subscribers last year according to data compiled by Enders Analysis, which estimated that low-cost rivals including Lebara, iD Mobile and Sky gained more than 1.5mn by comparison. They lost 724,000 in 2024.
The losses come as a wave of challengers prepare to enter the UK telecoms market with cut-price offerings designed to entice customers, including those from bank Monzo and retailer Lidl, which will further intensify retail competition.
Those brands are also likely to be joined by Digi, a Romanian-based operator which has already launched in several European markets such as Spain. Digi already offers WiFi services in the UK and said earlier this month that it planned to launch a UK mobile service.
Kester Mann, analyst at FDM CCS Insight, said the surge in growth of virtual providers reflected “a trend towards customers more actively seeking out affordable mobile plans amid the continued squeeze on household budgets.”
“This is supported by growth of online sales, lengthening replacement cycles for mobile phones and a growing willingness among consumers to consider non-traditional telecom brands,” he added.
The new entrants are mobile virtual network operators, or MVNOs, which strike wholesale deals to use the networks run by large telecoms groups, meaning they do not need their own infrastructure.
The set-up poses a double-layered challenge for network operators, who battle their MVNO rivals for customers while simultaneously trying to entice them into signing wholesale deals to use their infrastructure, rather than opt for that of their competitors.
One mobile network executive lamented that MVNOs “subtract value” from traditional operators, saying they wished someone would “remove them” from the UK market.
Others, however, have played down the MVNO threat.
“You’ve got to be careful, it’s a volume play with MVNOs,” BT boss Allison Kirkby told the FT, pointing to the fact that cheap tariffs mean a large number of customers are necessary for smaller groups to be viable.
“A lot of the customers that buy into MVNOs, they churn more frequently, much more frequently than the average customer that we have,” she added.
At the current rate, MVNO market share will grow from 21 per cent in 2025 to 26 per cent in 2030, according to estimates from FDM CCS.
Their growth has accelerated in recent years due to the advent of eSims, which allow customers to quickly sign up and download the service in a few clicks, as well as external factors such as the cost of living issues.
The 2025 merger of VodafoneThree also boosted MVNOs, after the two companies were forced to offer attractive wholesale offers to rivals in an effort to get the deal signed off by the UK’s Competition and Markets Authority.
“Great deals for MVNOs have arguably been a collective strategic mis-step by the operators, but the VodafoneThree remedies now tie them to that for many years to come,” Karen Egan, head of telecoms at Enders Analysis said.
BT, Virgin Media O2 and VodafoneThree declined to comment.