The theories of existing official documents or scholars of the law in "Ryonoshuge" (Commentaries on the Civil Statutes) says that earthenwares, used in the Imperial Court or government officials except for special earthenwares used for rituals, were provided by tributes of cho (tributes) and nenryo zakki (ware paid as a tribute) or shozei koeki (provision by shozei [the rice tax stored in provincial offices' warehouse]) and kyotoshi is considered to have only managed and done cashier job for earthenwares collected in the central government.
現存する公文書や『令集解』における明法家の説からは、祭祀に使う特殊な陶器を除いた宮中及び官司で用いられる陶器類は調・年料雑器による貢納や正税交易（正税を用いた調達）によって賄われ、筥陶司は中央に集められた陶器の管理・出納業務のみを行っていたと考えられている。