After the transfer of the headship, Ujimasa was first assigned to create a tax ledger (a list of territories and the amount of rice yield) of vassals of the Hojo clan (A land survey was conducted every change of a family head).
家督相続後、氏政が最初に行なった仕事が北条家所領役帳の作成（代替わりの検地）とされている。