Wado-kaichin was issued in order to establish the currency system like the one in the Tang Dynasty and also to cover the expenses used to move the capital to Heijo by the difference in the value between the bullion and currency value.
唐に倣い、貨幣制度を整えるため、また、ちょうど平城京遷都の直前だったため、遷都の経費を、銅地金と貨幣価値との差額で補う目的もあった。