Telefonica Brasil SA (Telefonica Brasil) is a subsidiary of Telefonica SA, provides fixed-line telecommunications services. The company provides fixed and mobile voice services, fixed and mobile broadband services, and ultra-broadband services such as Fiber to the Home (FTTH) and Fiber to the Curb (FTTC) services. As of December 2023, the company had market share of 38.7% in Brazil, based on accesses, with a strong position in post-paid mobile services having 41.5% market share, based on accesses. It also reached 17.7% of total market share in fiber-to-the-home (FTTH) accesses in Brazil. The company provides fixed voice services, mobile services, data services, pay TV services, network services, wholesale services and digital services. Its fixed voice services such as local, domestic long-distance and international long-distance calls both on the public and private regime. Its fixed local services include monthly subscription, activation, public telephones and measured services. Telefonica Brasil mobile portfolio includes voice and broadband internet access through third generation (3G) and fourth generation (4G) as well as value-added services. Its value-added-services mainly includes voice mail, caller identification, voice minutes in unlimited bundles to mobile phones of post-paid customers, ring tones; and other services such as cloud-based services to save texts, entertainment and music apps, multi-media backup, and advertising platforms. Telefonica provides wireless roaming services throughout Brazil as it has agreements with local companies. The company's data services comprise fixed broadband through xDSL technologies, coaxial cable and fiber (FTTH) and (FTTC), with speeds ranging from one megabit per second (Mbps) to one Gigaabit per second (Mbps). The company provides subscription-based television (Pay TV) services via DTH (direct to home) and Internet Protocol television (IPTV). As of December 2023, it covered 4,391 municipalities with 3G network, reaching 97.4% of Brazil’s population; 4,753 municipalities with 4G LTE reaching 96.3% of Brazil’s population and 3,633 municipalities with 4.5G LTE through carrier aggregation, reaching 89.6% of the Brazilian population. Telefonica Brasil provides wholesale services such as interconnection services to users of other network providers. The company also sells global system for mobile communication (GSM) and wideband code division multiple access (WCDMA) devices such as smartphones, handsets, broadband USB modems and devices.

The R&D arm of the company focuses on development, update and modernization of systems and evolution of products and services comprising features such as machine learning, cognitive computing, artificial intelligence and e-care. The company through its research and development projects consistently intends to innovate its products and services to keep up with growth expectations. In FY2023, the company incurred expenses of BRL57.9 million on R&D, which as a percentage of total revenue, stood at 0.1%.