mandatorily

This term is primarily used in legal, administrative, and formal regulatory contexts. It carries a heavy tone of obligation and authority, signaling that there is no room for discretion or optional participation. Because of its formal register, it is rarely used in casual conversation, where speakers prefer phrases like "have to" or "must."

Grammatically, as an adverb, it modifies verbs of requirement or action to specify that the action is a legal or rule-based necessity. It is often paired with verbs such as "required," "enforced," or "implemented" to emphasize the compulsory nature of a mandate.