When kogi (shogunate) cupellated silver paid by silver mine of tenryo (shogunal demesne) was entrusted to ginza, they made chogin from it and their income, buichi-gin, was determined to be 3% of the minting amount, while remaining part was paid to bakufu.
天領の銀山から上納された公儀灰吹銀を預り、丁銀を吹きたてた場合の銀座の収入である分一銀（ぶいちぎん）は鋳造高の3%とされ、残りは幕府に上納した。