Telefonica UK Ltd (Telefonica UK), a subsidiary of VMED O2 UK Ltd, is a provider of mobile telephony services to consumers and business customers. The company offers mobile telecommunications and value-added services including messaging, voice, data services, wearable devices, hardware and value add services including digital payments and insurance products. The company classifies its revenue in three categories: Mobile Service Revenue, Hardware and other revenue and Financing revenue. Telefonica UK provides products and services to public sectors, small and medium businesses, large enterprises, wholesale, and mobile virtual network operator partners. The company’s MVNO partners include Tesco mobiles, Sky Mobile, giffgaff and Virgin Mobiles. The company offers O2 Wi-Fi services, Wi-Fi calling, payment services, My O2 and O2 extras which provides access services through Amazon, Disney, and McAfee brands. It operates 2G, 3G, 4G and 5G networks in the UK. Telefonica UK's landline and telephony services include business landline, telemarketing numbers and mobile landline services. The company’s mobile and voice services consist of enterprise mobility management, IT and operations. Telefonica UK offers managed network services such as the Internet, connectivity services and managed solutions. Telefonica had long-standing network sharing with Vodafone, it shares network through mobile sites and 5G active equipment’s in the UK. As of December 2024, the company had 300 retail stores in the UK, including 60 franchise stores.