The answer depends on whether the deceased person had another person as an authorized co-lessee (or "owner") of the box and whether that person has a key. If not, resort to the probate court may be needed.
When there is no co-lessee with a key, a court order is required to access the box. To do this, a person must petition the probate court for an order. That order must include certain conditions under which the box shall be accessed. The order is then provided to the applicable financial institution and an opening can be scheduled. In most instances, the box will have to be drilled by a professional locksmith.
The initial opening of a safe-deposit box that is leased by the decedent must be conducted in the presence of any two of the following persons: 1) an employee of the institution where the box is located, 2) the personal representative, or 3) the personal representative's attorney of record. Each person who is present must verify the contents of the box by signing an inventory under penalties of perjury. The inventory must describe each item in the box. The personal representative must then file the safe-deposit box inventory, together with a copy of the box entry record from a date which is 6 months prior to the date of death to the date of the inventory. These must be filed with the court within 10 days after the box is opened. Unless otherwise ordered by the court, this inventory of the box contents and the attached box entry record is subject to inspection only by the persons entitled to inspect an inventory under the applicable provisions of Florida's Probate Code.