PROB §16342: (a) This section applies to a business or other activity conducted by a fiduciary if the fiduciary determines that it is in the interests of the beneficiaries to account separately for the business or

(a) This section applies to a business or other activity conducted by a fiduciary if the fiduciary determines that it is in the interests of the beneficiaries to account separately for the business or other activity instead of doing either of the following: (1) Accounting for the business or other activity as part of the fiduciary’s general accounting records. (2) Conducting the business or other activity through an entity described in subparagraph (A) of paragraph (2) of subdivision (a) of Section 16340. (b) A fiduciary may account separately under this section for the transactions of a business or other activity, whether or not assets of the business or other activity are segregated from other assets held by the fiduciary. (c) A fiduciary that accounts separately under this section for a business or other activity: (1) May determine the extent to which the net money receipts of the business or other activity shall be retained for any of the following purposes: (A) Working capital. (B) The acquisition or replacement of fixed assets. (C) Other reasonably foreseeable needs of the business or other activity. (2) May determine the extent to which the remaining net money receipts are accounted for as principal or income in the fiduciary’s general accounting records for the trust. (3) May make a determination under paragraph (1) separately and differently from the fiduciary’s decisions concerning distributions of income or principal. (4) Shall account for the net amount received from the sale of an asset of the business or other activity, other than a sale in the ordinary course of the business or other activity, as principal in the fiduciary’s general accounting records for the trust, to the extent the fiduciary determines that the net amount received is no longer required in the conduct of the business or other activity. (d) Activities for which a fiduciary may account separately under this section include all of the following: (1) Retail, manufacturing, service, and other traditional business activities. (2) Farming. (3) Raising and selling livestock and other animals. (4) Managing rental properties. (5) Extracting minerals, water, and other natural resources. (6) Growing and cutting timber. (7) An activity to which Section 16353, 16354, or 16355 applies. (8) Any other business conducted by the fiduciary.