v3.25.4
OTHER OPERATING INCOME AND EXPENSES (Details) - CHF (SFr)
SFr in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of attribution of expenses by nature to their function [line items]      
Marketing & commissions SFr (185.7) SFr (188.7) SFr (195.4)
Network related costs (117.2) (146.1) (150.5)
Professional services (69.5) (84.0) (111.6)
Facility & energy (64.2) (64.6) (54.4)
IT expenses (80.2) (99.2) (78.8)
Administration (39.8) (39.7) (39.5)
Call centre services (42.0) (40.8) (47.0)
Allowance for receivables (19.9) (30.8) (15.6)
Other expenses (4.6) (2.5) (66.1)
Total other operating expenses (623.1) (696.4) (758.8)
Capitalised labour as non-current assets 63.3 63.0 68.3
Other income 0.0 5.1 37.4
Total other operating income and capitalised labour SFr 63.3 68.1 105.7
Prior Period Reclassification Adjustments      
Disclosure of attribution of expenses by nature to their function [line items]      
Marketing & commissions   (0.1) 0.2
Network related costs   (24.5) (16.9)
Professional services   (21.7) (18.6)
Facility & energy   (1.9) (0.7)
IT expenses   41.6 29.4
Administration   5.0 0.1
Call centre services   6.1 7.8
Allowance for receivables   (4.5) (1.3)
Other expenses   0.0 0.0
Total other operating expenses   SFr 0.0 SFr 0.0