Called up share capital and other equity instruments - Maximum obligation to deliver HSBC Holdings ordinary shares (Details) - shares |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Share Capital, Reserves And Other Equity Interest [Abstract] | ||
| Maximum shares required to deliver all outstanding options (in shares) | 178,823,734 | 209,683,768 |
| Number of shares held in employee benefit trust (in shares) | 35,354,337 | 9,305,925 |