Synonyms of mandatory

2 Syllables

binding, needful, forced

3 Syllables

required, commanding, imperious, essential, hard-and-fast, compelling, bottom-line

4 Syllables

compulsory, departmental, requisite, bottomline, necessary

5 Syllables

compulsatory, obligatory, imperative, involuntary, irremissible, indispensable, prerequisite