Crimes Act 1961, s 59
New Zealand law recognises that there are sometimes valid reasons for a parent to use force against a child, like if the child is in danger, and needs to be grabbed back to safety. But it’s not legal to use force to “correct” or discipline a child. So, smacking a child as punishment is not legal in New Zealand.
A parent (or someone in the place of a parent, but not a teacher) is justified in using force against a child, as long as the force used is reasonable in the particular situation, only for these reasons:
to prevent or minimise harm to the child or another person (like if the child is about to touch a hot stove, or run onto a road), or
to prevent or stop the child engaging in criminal conduct, or
to prevent or stop the child engaging in offensive or disruptive behaviour (like carrying a child away from a situation they’re disrupting), or
to perform the normal daily tasks that are incidental to good care and parenting (like changing a nappy or giving a child medicine, even if they don’t want you to).
However, parents can’t use force “for the purpose of correction” – that is, to punish or discipline the child.
The police have the discretion to decide not to prosecute a parent for using force against a child if the offence is so inconsequential that it’s not in the public interest to bring charges.