All of the notes in this category have been collected from foreign countries around the world. Where possible, detailed information about each note has been obtained.

In many of the European countries, their national currencies have been withdrawn and replaced by the Euro. The former currencies including the Austrian schilling, the Belgian franc, the Finnish markka, the French franc, the Deutsche mark, the Greek drachma, the Irish pound, the Italian lira, the Luxembourg franc, the Dutch guilder, the Portuguese escudo and the Spanish peseta are no longer legal tender.

The symbol for the Euro is € and the international code for it is EUR. The Euro is currently used by a significant number of countries in the European Union. Several members of the European Union are not currently participating in the single currency and retain their own national currency.

There are two major catalogues for general world issues of banknotes. The first, which is no longer being updated is the Krause catalogue and its associated Pick numbers. Most notes issued through 2010-2015 have been assigned Pick numbers and will be shown here. The second, and quickly becoming the de facto standard, is The Bank Note Book by Owen W. Linzmayer. This outstanding resource is updated often and is constantly growing. All notes included in released chapters of the Bank Note Book will be assigned BNB numbers here. It should be noted that many specialized catalogues exist for individual countries. The most relevant example is Canada. For all countries other than Canada and the United States, this specialized cataloguing is beyond the scope of this website.

World banknotes are produced on a variety of substrates such as paper and polymer, with several subtypes including normal rag paper, Endurance™ high-strength paper, deckle paper, Guardian™ polymer, Safeguard® polymer and Tyvek® polymer. When known, the substrate of a banknote is identified by an icon, with lettered squares representing paper varieties and lettered circles representing polymer varieties. Several hybrid paper-polymer banknotes are also known to exist.

Foreign exchange rates are provided via a free API from Open Exchange Rates and are updated once per day. Where the currency of a banknote has been replaced, the face value is converted into the new currency before being converted to U.S. dollars.