If an executor of a will is obliged to file the inheritance tax declaration according to § 31 para. 5 Inheritance and Gift Tax Act (IGTA), he also has to ensure the payment of the inheritance tax (§ 32 para. 1 sent. 2 IGTA).
Based on these obligations the executor of a will is liable for the non-payment of the inheritance tax to the extent of his execution of a will (§§ 34, 69 General Fiscal Code). Nevertheless, this is only is the case if he acts intentionally or due to gross negligence.
Such a deficiency is at hand if the tax due cannot be guaranteed after the payments from the estate’s assets to the taxable persons were made and an additional tax payment was foreseeable at this point in time.
For more details regarding the obligations of executors of a will, administrators of a deceased’s estate or curators of the estate see Koeniger, The German Inheritance and Gift Tax, 2017, p. 333 et seqq.