There are two questions on the child's tax return: "Can you be claimed as a dependent?" and "Will the person who could claim you, actually claim you this year?"
If the child can be claimed as a dependent but answers No, that could be considered tax fraud. If the child answers "yes, I can be claimed as a dependent" but "no, the person who could claim me won't claim me", that will affect their eligibility for the AOTC and Lifetime Learning credit, and can–in some cases–allow the child to claim a credit where the parent is prevented by income.
However, even if the child answers "no, I can't be claimed as a dependent", the kiddie tax will apply unless the child provides more than half their own support, or their parents are deceased. The kid tax is calculated on a slightly different set of rules.
