In the UK, you may be eligible for Child Benefit if you are responsible for a child under 16, or under 20 if they are in approved education or training. You do not have to be the child's parent; you can also claim if you are their guardian or an adoptive parent. However, if you or your partner earn over £50,000 a year, your Child Benefit may be reduced. For more detailed information, it's best to check the official gov.uk page on Child Benefit eligibility.