Cal. Probate Code § 879

Unless otherwise ordered by the court, directed by the user, or provided in a trust, a custodian shall disclose, to a trustee that is not an original user of an account, the catalogue of electronic communications sent or received by an original or successor user and stored, carried, or maintained by the custodian in an account of the trust and any digital assets, other than the content of electronic communications, in which the trust has a right or interest if the settlor of the trust is deceased and the trustee gives the custodian all of the following: (a) A written request for disclosure in physical or electronic form. (b) A certified copy of the death certificate of the settlor. (c) A certified copy of the trust instrument or a certification of trust under Section 18100.5. (d) A certification by the trustee, under penalty of perjury, that the trust exists and that the trustee is a currently acting trustee of the trust. (e) If requested by the custodian, any of the following: (1) A number, username, address, or other unique subscriber or account identifier assigned by the custodian to identify the trust’s account. (2) Evidence linking the account to the trust.