''Lex monetae'' is a

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

phrase which means that a sovereign state chooses which

currency A currency is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins. A more general definition is that a currency is a ''system of money'' in common use within a specific envi ...

it will use and that the meaning of units of above-mentioned currency is determined by the law of the country whose money is in question. The concept has been identified as a potential problem if the

Eurozone The euro area, commonly called the eurozone (EZ), is a Monetary union, currency union of 20 Member state of the European Union, member states of the European Union (EU) that have adopted the euro (Euro sign, €) as their primary currency ...

breaks up or a member state decides to leave it, since debts in

euro The euro (currency symbol, symbol: euro sign, €; ISO 4217, currency code: EUR) is the official currency of 20 of the Member state of the European Union, member states of the European Union. This group of states is officially known as the ...

s may turn into debts owed in another currency. Conversion would be at a rate determined by the nation in question, and no party to a contract or transaction will have the right to default on it.

References

Currency Latin words and phrases {{italic title