Although the policy can vary in each credit union, usually the child should be present with a parent or guardian when opening the account.
In some cases, for credit unions in the Republic of Ireland; if the child is not deemed old enough to withdraw money, (for example they are under the age of 7) the account may be opened by a third party (i.e. godparents or grandparents). The third party can nominate a parent or guardian to operate the account until the child is deemed old enough to sign and withdraw money themselves. (e.g. 7 years of age).