The phrase "up to individual" means that a decision or preference is left to the discretion of each person. Antonyms, or words with opposite meanings, could include "mandatory," "compulsory," or "collective." These words indicate something that is required or decided upon for a group, rather than allowing for individual choice. Other antonyms might include "inflexible," "uniform," or "consensus," which suggest a lack of flexibility or diversity in decision-making. Ultimately, the opposite of "up to individual" is any approach that prioritizes the needs or will of the majority over individual autonomy, whether through laws, social norms, or other mechanisms.