For the CRA, an eligible dependant is a qualifying relative: a parent or grandparent; a child, grandchild or sibling under 18; or an adult child, grandchild or sibling with a mental or physical infirmity who lives with you and who you support. Generally, you must be single, divorced, separated or widowed when you support them (it's an alternative credit to the "amount for spouse or common-law partner").

For full rules and exceptions, see the CRA’s eligible dependant page. If Better Tax asks "Who is your eligible dependant?" it simply means your return may qualify based on your current answers.

If you have a custody or separation agreement, it may dictate which partner can claim this credit on behalf of a shared child.