v3.25.4
Property, Plant And Equipment (Details 1) - BRL (R$)
R$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period R$ 46,812,381 R$ 46,318,147
Additions [1] 10,108,587 11,075,032
Revaluation increase (decrease), property, plant and equipment [2] (239,653) (141,532)
Net transfers [3] (1,298) (35,058)
Subletting (4,873) (65,290)
Depreciation, property, plant and equipment (10,994,217) (10,339,983)
Assets held for sale – Property, plant and equipment (8,761)  
Balance at end of the period 47,357,040 46,812,381
Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 185,180,626  
Balance at end of the period 195,098,914 185,180,626
Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (138,368,245)  
Balance at end of the period (147,741,874) (138,368,245)
Liabilities for the acquisition of a company - Vita IT    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment   1,065
FiBrasil Infraestrutura e Fibra Otica S.A. ("FiBrasil")    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 1,679,502  
Samauma    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 217  
Telefonica Cibersegurana e Tecnologia Do Brasil    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 5,155  
Switching and transmission equipment    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 22,770,806 23,266,868
Additions [1] 140,156 162,171
Revaluation increase (decrease), property, plant and equipment [2] (2,810) (10,653)
Net transfers [3] 3,235,811 3,266,774
Depreciation, property, plant and equipment (4,437,238) (3,914,354)
Balance at end of the period 21,709,525 22,770,806
Switching and transmission equipment | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 91,758,158  
Balance at end of the period 94,868,938 91,758,158
Switching and transmission equipment | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (68,987,352)  
Balance at end of the period (73,159,413) (68,987,352)
Switching and transmission equipment | Telefonica Cibersegurana e Tecnologia Do Brasil    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 2,800  
Infrastructure    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 15,990,041 14,929,179
Additions [1] 3,636,211 4,707,950
Revaluation increase (decrease), property, plant and equipment [2] (217,861) (111,421)
Net transfers [3] 547,154 358,091
Subletting (4,873) (65,290)
Depreciation, property, plant and equipment (4,105,108) (3,829,001)
Assets held for sale – Property, plant and equipment (7,399)  
Balance at end of the period 17,402,210 15,990,041
Infrastructure | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 47,318,029  
Balance at end of the period 52,291,576 47,318,029
Infrastructure | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (31,327,988)  
Balance at end of the period (34,889,366) (31,327,988)
Infrastructure | Liabilities for the acquisition of a company - Vita IT    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment   533
Infrastructure | FiBrasil Infraestrutura e Fibra Otica S.A. ("FiBrasil")    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 1,563,540  
Infrastructure | Telefonica Cibersegurana e Tecnologia Do Brasil    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 505  
Lending equipment    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 5,510,213 5,401,694
Additions [1] 90,341 85,285
Revaluation increase (decrease), property, plant and equipment [2] (17) (469)
Net transfers [3] 1,961,984 2,185,708
Depreciation, property, plant and equipment (2,206,428) (2,162,005)
Balance at end of the period 5,356,093 5,510,213
Lending equipment | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 31,701,975  
Balance at end of the period 32,937,369 31,701,975
Lending equipment | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (26,191,762)  
Balance at end of the period (27,581,276) (26,191,762)
Terminal equipment    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 212,486 421,385
Additions [1] 590 32
Revaluation increase (decrease), property, plant and equipment [2]   (536)
Net transfers [3] 17,612 36,752
Depreciation, property, plant and equipment (113,084) (245,147)
Balance at end of the period 117,604 212,486
Terminal equipment | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 6,582,403  
Balance at end of the period 6,585,887 6,582,403
Terminal equipment | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (6,369,917)  
Balance at end of the period (6,468,283) (6,369,917)
Land    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 239,265 249,536
Revaluation increase (decrease), property, plant and equipment [2] (643) (10,271)
Assets held for sale – Property, plant and equipment (1,362)  
Balance at end of the period 238,078 239,265
Land | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 239,265  
Balance at end of the period 238,078 239,265
Land | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 0  
Balance at end of the period 0 0
Land | FiBrasil Infraestrutura e Fibra Otica S.A. ("FiBrasil")    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 818  
Other property, plant and equipment    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 453,959 512,930
Additions [1] 171,553 117,026
Revaluation increase (decrease), property, plant and equipment [2] (6,750)  
Net transfers [3] (53,752) 12,947
Depreciation, property, plant and equipment (132,359) (189,476)
Balance at end of the period 434,919 453,959
Other property, plant and equipment | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 5,945,185  
Balance at end of the period 6,078,455 5,945,185
Other property, plant and equipment | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period (5,491,226)  
Balance at end of the period (5,643,536) (5,491,226)
Other property, plant and equipment | Liabilities for the acquisition of a company - Vita IT    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment   532
Other property, plant and equipment | FiBrasil Infraestrutura e Fibra Otica S.A. ("FiBrasil")    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 1,061  
Other property, plant and equipment | Telefonica Cibersegurana e Tecnologia Do Brasil    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 990  
Construction in progress    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 1,635,611 1,536,555
Additions [1] 6,069,736 6,002,568
Revaluation increase (decrease), property, plant and equipment [2] (11,572) (8,182)
Net transfers [3] (5,710,107) (5,895,330)
Balance at end of the period 2,098,611 1,635,611
Construction in progress | Gross carrying amount    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 1,635,611  
Balance at end of the period 2,098,611 1,635,611
Construction in progress | Accumulated depreciation and amortisation    
PROPERTY, PLANT AND EQUIPMENT    
Balance at beginning of the period 0  
Balance at end of the period 0 R$ 0
Construction in progress | FiBrasil Infraestrutura e Fibra Otica S.A. ("FiBrasil")    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment 114,083  
Construction in progress | Telefonica Cibersegurana e Tecnologia Do Brasil    
PROPERTY, PLANT AND EQUIPMENT    
Acquisitions through business combinations, property, plant and equipment R$ 860  
[1] Additions from property and equipment mainly refers to: (i) in 2025 Investments were primarily directed towards expanding the 5G mobile network and strengthening FTTH to support the growth of connected customers. These investments demonstrate the Company's commitment to the quality of services provided, ensuring robust and consistent commercial performance throughout the year, in both B2C and B2B; .(ii) in 2024: Investments were primarily directed towards accelerating the 5G mobile network, as well as strengthening transmission backhaul, backbone and network, and FTTH customers. These were some of the initiatives that boosted our commercial growth this year, reinforcing our commitment to the quality of our services and ensuring healthy and consistent growth.
[2] In infrastructure, includes the amounts of R$213,077 and R$74,258 in 2025 and 2024, respectively, referring to the cancellation of lease agreements.
[3] Total balances refer to transfers between classes of fixed and intangible assets (Note 14.c.).