Why would an administration bond have a fixed amount?

One reason, an adminsistrator Bond  is required, is the estate might appreciate in value, additional assets may be discovered but not reported to the court. This is not at all uncommon, it may be inconvenient to report. The fiduciary may deliberately fail to report in order to avoid having the bond increased and to avoid additional premium and cost. Whether the additional bond is furnished or not, the surety is liable up to the amount of the loss, but not in excess of its bond penalty. Therefore, the proper basis of premium computation is the amount of the bonds, not the amount of the personal property.