The Letters Testamentary Book contains an index by decedent's last name, and the letters testamentary. The court grants the executor the authority to act on behalf of the estate in the letters testamentary. If there is a will, the legal representative is called an executor. An administrator is appointed by the court when there is no will and the authority to act of behalf of the estate is granted by the court in the letters of administration. As of 1998, these letters are filed in the minutes book. A list of Letters Testamentary Books by date can be found below.

Information found in these books include:
Decedent's name
Date will was proven
Form in which will was proven (solemn or common)
Date will admitted to record by order
Executor's name
Whether or not inventory and returns are required
Name of probate judge
Date recorded