0 Euro - San Marino 2021

San Marino is not a eurozone member and issues no euro banknotes of its own — these zero-denomination souvenir notes exist entirely outside monetary law, produced by Oberthur Fiduciaire in France for the collector market under a framework that allows licensed printers to produce commemorative pieces styled after euro format without carrying legal tender status. The issuing "authority" is nominal at best.

Oberthur has produced dozens of these for various European microstates and tourist destinations since the souvenir note market expanded in the mid-2010s. Collectibility depends almost entirely on print run figures, which are controlled by the distributor rather than any central bank.