Many applications of metrology have a legal aspect, such as when there is a societal need to protect both the buyer and seller in a commercial exchange of a commodity or a service provided, or where measurements are used to apply a sanction. While the details might vary considerably, virtually all countries provide such protections through their legal systems, and so they need a Law on Metrology that covers how measurements and measuring instruments are to be treated in a legally acceptable manner. Furthermore, since there is an increasingly global aspect to many of these areas involving measurement, a country’s Law on Metrology should take this global aspect into account as far as possible.