v3.26.1
Retirement benefit obligations - Movement (Details) - CHF (SFr)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Defined benefit plans    
Net defined benefit (liability) asset at beginning of period SFr (164,251)  
Net defined benefit (liability) asset at end of period (371,608) SFr (164,251)
Defined benefit obligation    
Defined benefit plans    
Net defined benefit (liability) asset at beginning of period (2,108,384) (9,138,045)
Current service cost (30,086) (80,111)
Past service cost   520,360
Interest (cost) income (21,598) (57,212)
Employee contributions (20,929) (70,748)
Actuarial (loss)/ gain arising from changes in financial assumptions 212,470 (176,520)
Actuarial gain on experience adjustment (459,035) (184,372)
Benefits paid/deposited (2,698,455) 7,078,264
Net defined benefit (liability) asset at end of period (5,126,017) (2,108,384)
Fair value of plan assets    
Defined benefit plans    
Net defined benefit (liability) asset at beginning of period 1,944,133 8,694,521
Interest (cost) income 19,441 53,688
Employee contributions 20,929 70,748
Employer contributions 39,464 92,285
Plan assets loss 31,987 111,155
Benefits paid/deposited 2,698,455 (7,078,264)
Net defined benefit (liability) asset at end of period SFr 4,754,409 SFr 1,944,133