Typically, if assets such as stocks, bonds, investment accounts are in an individual account of the deceased (with no beneficiary designation), the financial institution (or title company if real estate is owned by the deceased) will require Letters Testamentary to show that the court has authorized the Executor to act on behalf of the estate to gather and transfer the assets. The Executor would also have the authority to deal with taxing authorities and to reimburse for those who advanced funeral expenses, last illness expenses, etc. If there is no valid will and heirs can agree, an Independent Administrator can be appointed by the Court and Letters of Administration can be granted so that the Administrator can act on behalf of the estate. If there is no agreement between the heirs on who can act on behalf of the estate, then the Court would have a Dependent Administration and the court would oversee payment of bills, whether property could be sold, require an annual accounting, etc.