On June 25, 2025, Three UK and its MVNO partners (iD Mobile, Smarty) suffered a massive disruption from 7:45 am to around 10 pm, leaving over 9,300 users unable to make or receive voice calls and SMS. Data services largely remained though some experienced partial drops, and emergency call reliability was also questioned. Thousands turned to social media—“No incoming or outgoing calls are becoming regular occurrences now”—while Three offered apologies, monitoring updates, and potential compensation. The outage follows similar incidents earlier this year, raising questions about network resilience amid the Vodafone–Three merger.

Banking Apps Add Fuel to the Fire

Meanwhile, UK banks have seen a dramatic uptick in IT failures. NatWest recently apologized after a mobile app crash blocked millions of users from accessing accounts following a faulty update. Dozens of payday incidents involving Lloyds, Halifax, Barclays, TSB, and Nationwide have disrupted essential transactions. Between 2023 and early 2025, nine major banks reported over 803 hours of downtime—equivalent to 33 days—with Barclays alone facing up to £12.5 million in potential compensation.

Root Causes: Outdated Systems, Complexity & Tech Debt

Industry experts attribute these widespread failures to ageing legacy systems, complexity from cloud migrations, and over-reliance on common suppliers. Many banks still run core systems from the 1990s, lacking capacity for today's digital demands. Similar network issues are echoed by Ookla data: about 27% of UK smartphone users experience outages monthly, with many considering switching providers due to poor communication during disruptions.

Impact on Consumers & Business

These outages have real-world impact: missed payments, inability to pay staff, emergency call failures, and general distrust. SMEs and families—especially those paid monthly—can suffer serious consequences. Regulators, including Ofcom and the Treasury Committee, are calling for accountability, transparency, and upgrades tied to strong consumer protection measures and potential compensation schemes.

What Needs to Happen: Modernise or Perish

Experts and MPs agree UK’s mobile operators and banks must accelerate investment in digital resilience. recommendations include:

• Replacing legacy platforms with cloud-backed, API-first systems.
• Embedding AI-powered monitoring and predictive maintenance.
• Adopting fault-tolerant architectures like those used by Monzo.
• Improving customer communications with real-time outage alerts.

Failing to modernise risks ongoing reputational damage, regulatory penalties, and consumer churn—as millions could switch providers in search of reliability.