Am I required to seek permission from the author(s) before using OER?


No. OER use Creative Commons (CC) licenses, each of which specifies the permissions that the author has proactively granted future users of their work (e.g., reuse, revise, remix, redistribute, and retain). The adoption of a CC license removes the need for users to contact authors to seek permission for reuse.

Image source (CC-BY-NC)

Creative Commons, CC, OER, permission, author, reuse