Facts
[A.] ___ (the appellant) and [D.B.] are the unmarried parents of [B.B.] and [C.B.] . The children are under joint parental custody, with the mother exercising care. The appellant has lived and worked in London since 2005. With maintenance agreements dated February 1, 2005, he undertook to pay monthly child support for the children.
In 2012, the mother filed a claim on behalf of the children with the District Court for modification of the maintenance contributions. By judgment of June 11, 2014, the District Court ordered the appellant to pay higher maintenance contributions. The children appealed against this to the Cantonal Court of Valais.
By judgment of December 22, 2016, the Cantonal Court ordered the appellant to pay further increased maintenance contributions. The present appeal by the appellant against this judgment is directed to the Federal Supreme Court.
Considerations
The Federal Supreme Court first examines whether there has been a violation of the right to be heard. It denies this, as the Cantonal Court has sufficiently explained the reasoning for the exclusion of the child allowances from the maintenance contributions and the rejection of the maintenance contribution proposed by the appellant.
On the merits, the Federal Supreme Court objects that the Cantonal Court has credited the appellant with a hypothetical income based on the wage level in Switzerland. Since the appellant has lived and worked in London for over 10 years, it is not reasonable to expect him to give up his life there in order to earn a higher income in Switzerland. The Federal Supreme Court therefore refers the case back to the District Court for a new determination of the maintenance.
Furthermore, the Federal Supreme Court criticizes that the Cantonal Court has granted a flat-rate surcharge of 18% on the Zurich tables for…