Buichigin was an income that Ginza received when they minted Chogin from the cupellated silver used for the Shogunate, and this income was set to 3% of cupellated silver they received.
公儀灰吹銀から丁銀を吹きたてる場合の銀座の収入である分一銀（ぶいちぎん）は渡された灰吹銀に対する3%と設定された。