牌照 most commonly refers to vehicle license plates (车牌照). In business contexts it means a license/permit. Synonym: 车牌 (chēpái) for license plates specifically.
culture
In Shanghai, license plates are auctioned and can cost over 100,000 RMB (~$14,000), making them among the most expensive in the world. This is why 上海牌照 is a culturally loaded phrase.