Facts

The testator [D.] (born 1936) died on 13 June 2018 in [U.] . He left as statutory heirs the three sons [A.] (appellant), [B.] (respondent 1) and [C.] (respondent 2).

On 11 January 2019 the District Court of Uster issued a certificate of inheritance stating that the three sons were the only statutory heirs. On 18 March 2020 the appellant filed a holograph will dated 22 November 2016 for opening. Under it, the testator had designated the respondents as heirs to their compulsory portion, assigned the remainder of the estate to the appellant and appointed him as executor. By judgment of 8 July 2020 the District Court set aside the earlier certificate, announced a new one and issued the appellant an executor's certificate.

On 31 July 2020 [B.] filed an objection to the announced certificate. By judgment of 12 August 2020 the District Court held that no certificate of inheritance was to be issued as long as the objection was not resolved, and ordered administration of the estate, which it assigned to the Uster Notary's Office.

By judgment of 5 November 2020 the Higher Court of the Canton of Zurich dismissed the appellant's appeal. It reasoned that an appointed heir may not receive a certificate while his entitlement is disputed, and that a conflict of interest exists between the heirs, so that administration could not be entrusted to the appellant as executor.

The appellant filed a subsidiary constitutional complaint with the Federal Supreme Court and requested the issuance of a certificate of inheritance or, alternatively, remittal of the matter, and, subalternatively, his appointment as estate administrator. The Federal Supreme Court granted suspensive effect to the complaint. The Higher Court waived a response; the respondents did not submit observations.

Considerations

The subsidiary constitutional complaint is the correct remedy, since the amount in dispute of CHF 30,000.-- (Art. 74 para. 1 let. b FSCA) is not reached and no question of fundamental importance arises (Art. 74 para. 2 let. a FSCA). The appellant has standing under Art. 115 FSCA. The strict principle of complaint under Art. 106 para. 2 FSCA applies; complaints of arbitrariness must be set out in detail.

Under Art. 559 para. 1 CC, a certificate of inheritance is issued upon request to both appointed and statutory heirs if their entitlement to inherit is not disputed. The competence of the authority is limited and provisional; the substantive legal position is reserved to the civil court. Information on the shares of the estate is not a necessary component of the certificate and has no legal significance. A deviating cantonal practice does not change this.

The objection was directed solely against the allocation of the disposable portion to the appellant, not against his entitlement to inherit in principle. Since the entitlement of all parties is established and would not lapse even if the will were invalid, there is no danger to third parties. The objection therefore does not stand in the way of issuing the certificate of inheritance. The Higher Court thus grossly violated Art. 559 para. 1 CC; the result is untenable and arbitrary.

The order of administration of the estate is based on Art. 554 para. 1 no. 4 and Art. 556 para. 3 CC on a need for the heirs to be protected, particularly in case of disagreement. The first ground relied on by the Higher Court (objection as a ground under established practice) falls away with the issuance of the certificate. The second ground, a civil dispute between the heirs over the auction of the parental property, nevertheless establishes a conflict of interest, the assumption of which is not manifestly untenable. The appellant does not substantively engage with the judgment of 8 July…