compulsory

US /kəmˈpʌl.sɚ.i/
UK /kəmˈpʌl.sɚ.i/
"compulsory" picture
1.

required by law or a rule; obligatory

:
•
School attendance is compulsory for children up to the age of 16.
•
Wearing a helmet is compulsory when riding a motorcycle.
:
mandatoryobligatoryrequiredrequisiteenforced
:
optionalvoluntarydiscretionary