A customs union removes trade barriers and reduces or removes customs duties between member countries, but does not allow free movement of capital and labor. A common market goes further by promoting duty-free trade and free movement of labor and capital among members. Geocentric companies operate globally to achieve both local and global objectives, with subsidiaries contributing unique competencies. Transfer pricing is the price at which divisions of a company transact internally, and is used to evaluate business unit performance and potentially shift earnings between tax jurisdictions. Letter of credit is a bank guarantee that ensures timely payment for imports by the buyer.