File an amended return for the estate or trust; Claim withholding. There is no estate tax in California.However, residents may have to pay a federal estate tax. Generally, the estate tax return is due nine months after the date of death. A six month extension is available if requested prior to the due date. In this case, it is advisable for the trust to file a fiduciary income tax return as long as this possibility exists (i.e. , for one year following the last. When filing as an executor of estate, on the Form 1040, include only income and expense items up to the date of death. The executor of a California estate is typically required to file Form 1040 for any deceased person who earned an income before passing away. Estate taxes in California are due and payable on or before nine months following the date of death.