Does the Number of Banknotes in Circulation Already Exceed 900 Billion?

If every central bank and monetary authority were to consistently publish the number of banknotes in circulation, this article wouldn’t be necessary. However, that isn’t the case, and the question is raised every now then in discussions. Various estimates, some around 550 billion, are cited in industry reports and presentations, which prompted me to dig deeper as the numbers seemed low. This article highlights some of the challenges involved when considering the question and provides an estimate for further discussion.