A notification obligation is the formal duty to report a qualifying cyber incident to a regulator, sector authority, or other designated body. The rule usually specifies what must be reported, who must report it, and within what deadline. The obligation is separate from internal incident handling: an organization can contain an attack, but still be required to notify an external authority because the event meets a legal threshold.
In cyber security, notification obligations matter because they turn technical incidents into compliance tasks. Teams need clear criteria for severity, affected systems, data impact, and applicable regulatory category so they can trigger the right workflow quickly. In real defenses, this means building reporting steps into incident response playbooks, preserving evidence, and maintaining accurate timelines. In attacks, adversaries may try to exploit confusion or delay, so knowing the obligation in advance helps organizations respond both technically and legally.