The best interests of the child (UNCRC Article 3) shall be a primary consideration in all decisions and actions that concern the child. Understanding the best interests of the child requires decision-makers to assess the needs of the child in a comprehensive way and to take those needs into account and assign due weight to each of them when making decisions in relation to the child. Promoting the best interests of the child requires due attention to other general principles under the Convention:  the right to non-discrimination (Art. 2), the right to live, survival and development of the Child (Art. 6), and the right to be heard (Art. 12).

The Committee on the Rights of the Child explains the best interests principle as a three-fold concept: a substantive right; a fundamental, interpretive legal principle; and a rule of procedure.

As a substantive right, Article 3.1 is considered directly applicable and can be invoked before a court. Each child has the right to have their  best interests assessed and taken as a primary consideration when different interests are being considered to reach a decision.

As a fundamental, interpretive legal principle, the best interests principle offers guidance for the application of laws: when there is room for interpretation and discretion in applying a specific law, the interpretation which most effectively serves the best interests of the child shall be applied.

As a rule of procedure, the principle implies that decision-making processes concerning children individually or collectively, in particular those aimed at assessing and determining the best interests of a child or a group of children, need to be transparent and explain the possible positive or negative impact of the decision on the child or a relevant group of children.

Committee on the Rights of the Child, General Comment No. 14 (2003) on the right of the child to have his or her best interests taken as a primary consideration, CRC /C/GC/14, 29 May 2013, para. 6.