The history of mail and postage stamps of Andorra covers the development of postal services in this dwarf state located in the Pyrenees between Spain and France. A special feature of Andorra's postal service is its dual nature: Spanish and French post offices operate on the territory of this principality, using the postal payment marks of Spain and France, respectively. Collecting and studying postage stamps and other philatelic materials from Andorra is quite popular. There are two known public associations of people interested in the history of mail and postage stamps of Andorra: the Society for the Study of Philately and Postal Affairs of Andorra (Philandorra) and the Circle for the Study of Philately of Andorra.