Facts

[B.B.] , born in 2002, is the son of [C.B.] and [A.] . The unmarried parents had concluded a maintenance agreement in 2002, in which the father undertook to pay a monthly maintenance contribution of CHF 1,070.-- for the child until his majority. In 2009, the parents separated. Subsequently, [A.] made payments of varying amounts, but at least to the extent of the contractual obligation. On 15 June 2014, [B.B.] , represented by his mother, filed a claim with the Cantonal Court of Zug for the payment of child support of CHF 2,500.-- per month until the age of 18 or until the completion of initial training, retroactively from October 2013. The Cantonal Court ordered [A.] to pay a (indexed) monthly maintenance contribution of CHF 2,200.-- plus any child allowances until the majority of the plaintiff. [A.] appealed to the High Court of the Canton of Zug, requesting the dismissal of the claim, or alternatively, the remission for further clarification and new assessment. In a cross-appeal, [B.B.] requested the award of the maintenance contribution beyond the age of majority until the completion of appropriate initial training. The High Court dismissed the appeal and the cross-appeal, to the extent that it entered into them, and confirmed the decision of the court of first instance.

Considerations

The Federal Court examined whether the increased cash requirement since the conclusion of the maintenance agreement led to an increase in the child maintenance contribution and, if so, whether the lower court's determination of the contribution withstands federal law. The High Court had considered that a child's needs notoriously increase with age. Since the question of whether this increasing need was taken into account at the time of the conclusion of the maintenance agreement could no longer be reconstructed, the agreement had to be interpreted according to the principle of trust. Given the high income of the child's father and the lower income of the child's mother, it would have been unreasonable if the child's father had not had to pay additional maintenance despite the child's increasing needs. Therefore, it had to be…