cOAlition S is an informal alliance of organisations and institutions that fund and/or perform research activities, and that have publicly expressed their intention to work together towards the implementation of the principles of Plan S. cOAlition S does not have any autonomous legal capacity. The individual organisations remain fully responsible for implementing their Plan S-aligned Open Access policies, as stated in the cOAlition S Terms of Reference.
The composition of the Leaders’ Group and the Executive Steering Group is available here.
The cOAlition S Office was set up in January 2020 and is hosted by the European Science Foundation (ESF) in Strasbourg, to support the work of cOAlition S.

| ACTIVITY / SPENDING (EUR) | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
| Human resources & related | 273700 | 427000 | 505674 | 542100 | 399576 | 300052 |
| Software development | 334000 | 287400 | 439378 | 388800 | 472361 | 200437 |
| Communication | 5250 | 6250 | 15000 | 5000 | 15736 | 2433 |
| Commissioned studies | 30000 | 34000 | 56393 | 91300 | 142485 | 0 |
| Legal & administrative | 13700 | 18750 | 93750 | 0 | 57076 | 37320 |
| Travel | 0 | 0 | 12500 | 62500 | 20952 | 4925 |
| Total | 665.650 | 773.400 | 1.122.695 | 1.089.700 | 1.108.186 | 545.167 |
The cOAlition S Office staff and activities are funded by cOAlition S funders’ contributions and grants. Human resources represented 2.3 FTE in 2020, 2.8 FTE in 2021, 3.5 FTE in 2022-2023, 3 FTE in 2024 and 2 FTE in 2025, including staff and consultancy. Software development mainly covered the costs of the Journal Checker Tool and the Journal Comparison Service (that was sunsetted in early 2025). Travel and event expenses covered notably the Plan S promotion activities. More information about our activities is available in the annual review series.