15 Centimos Monarchy stamp; countermark in one horizontal line

A stamp coin, cardboard coin, cardboard banknote or cardboard coin was a means of payment consisting of a disc of this material, about 35 millimetres in diameter and weighing approximately 0.5 grams, issued "on a temporary basis" by the Government of the Second Spanish Republic by ministerial order promulgated in Barcelona on 24 February 1938 and provided free of charge by the Fábrica Nacional de Moneda y Timbre in order to try to mitigate the progressive scarcity of metal (especially silver and copper) inherent in the last days of the Spanish Civil War, which is why it is usually considered by specialists as a "currency of necessity" or "emergency currency".

On the reverse (reddish brown), the republican national coat of arms appeared, while the obverse (brown) was left free in order to later affix a stamp of which determined its face value, stipulated between 1 centimo and 1.50 pesetas.

They were printed at the facilities of the Fábrica Nacional de Moneda y Timbre (National Mint and Stamp Factory) in Aspe (Alicante), known as "Factory D",​ and despite their initially "transitory" nature, they were not withdrawn from circulation until the end of the Civil War, specifically, until July 15, 1939 (according to the decree of June 9),​ that is, at the same time that all the "paper money put into circulation by the enemy" was collected,​ since, given the evolution of the conflict, it was not possible to establish another alternative means of payment that would render them useless.

There are many counterfeits. The simplest methods for detecting a counterfeit stamp coin: if the stamp is canceled (used) the coin is counterfeit and if the black circle surrounding the coat of arms is not stamped, i.e. it should be raised downwards (sunken), the coin is also counterfeit.