The majority of research journals charge authors an article processing fee (APC) to make an article open access at the time of publication. Costs are based on known 2021 APC costs for journals in which WCS published. For other journals, an estimate of $2,500 per article has been used based on the 2021 known cost averages. Some journals also allow published articles to be made open access retroactively, also for an approximate average cost of $2,500 per article. The right to make an article open access post-publication is limited to the primary or corresponding author.