The executor/administrator can be removed by the Court for failure to perform such duties. They can also be subject to possible civil and criminal penalties for improper conversion of estate property.
The executor/administrator is also responsible for filing estate tax returns and income tax returns for the decedent and the estate. They can be held personally responsible for their failure to file these returns.
In addition, they owe the beneficiaries of the estate a fiduciary duty. In law, this is the highest duty owed to another. The executor has a duty to protect, manage, and care for the estate assets as if the assets were his own. If the executor/administrator is not careful and dilligent, he or she can breach the fiduciary duty owed to the beneficiary and be personally responsible. For example, a house is worth $150,000. The executor fails to get it appraised and sells it for $100,000. He could be liable for the $50,000 in lost value.