Cal. Code Regs. tit. 18 § 13409
If a transferee under a will, an heir of an intestate or a transferee of an inter vivos transfer subject to inheritance tax disclaims any interest in the estate of the decedent or the property transferred, in whole or in part, pursuant to the provisions of Chapter 11 (commencing with Section 190) of Division 1 of the Probate Code, the interest disclaimed is treated as if the beneficiary disclaiming had predeceased the person who created the interest and said interest is taxed as a transfer from the decedent to the person who takes by reason of the disclaimer, provided all of the following requirements are satisfied:
To be effective, the disclaimer must be filed within a reasonable time after the disclaimant acquires knowledge of the interest. The presumption set forth in Section 190.3 of the Probate Code shall apply in determining whether a disclaimer has been filed within a reasonable time.
In the case of interests created by will or arising from intestate succession, the disclaimer shall be filed with the superior court in the county in which the estate of the decedent is being administered; if there is no administration, the disclaimer shall be filed with the superior court in the county in which administration would be proper.
In the case of an interest created by an inter vivos trust subject to the inheritance tax, the disclaimer shall be filed with the trustee then acting.
If a transferee under a will, an heir of an intestate or a transferee of an inter vivos transfer subject to inheritance tax disclaims any interest in the estate of the decedent or in the property transferred, in whole or in part, pursuant to the provisions of Chapter 11 (commencing with Section 190) of Division 1 of the Probate Code, and the date of death of the decedent is prior to August 16, 1972, the tax is nevertheless computed as though no disclaimer had been filed.
NOTE: Reference: Section 13409, Revenue and Taxation Code.
Cal. Code Regs. Tit. 18, § 13409