Why some countries share a currency, and others use someone else’s

Every country on this site has a currency field, and it quietly implies something that is not true: that each of the 195 countries has its own money. A large number of them do not, and the reasons split into a few distinct patterns worth knowing separately.

A currency union is not a political union

The clearest case is the euro. Around twenty countries use it, and using it requires no other form of integration — Montenegro and Kosovo both use the euro unilaterally without being EU members at all, while San Marino, Vatican City, Monaco and Andorra each use it under individual monetary agreements. Not every EU member uses it either: Denmark and Sweden have stayed out, by opt-out and by choice respectively, and several newer members are still working toward joining.

The Eastern Caribbean dollar is a smaller, less-discussed version of the same idea. Six independent countries — Antigua and Barbuda, Dominica, Grenada, Saint Kitts and Nevis, Saint Lucia and Saint Vincent and the Grenadines — share it, each with its own government, none with a vote over the others' fiscal policy. The currency is fixed to the US dollar and managed by a regional central bank.

Two francs that are not interchangeable

Fourteen African countries use a currency called the CFA franc, and there are two of them. The West African CFA franc circulates in Senegal, Mali, Ivory Coast, Burkina Faso, Niger, Togo, Benin and Guinea-Bissau. The Central African CFA franc circulates in Cameroon, Gabon, Chad, the Republic of the Congo, the Central African Republic and Equatorial Guinea. Both are pegged to the euro at the same fixed rate and both grew out of the former French colonial currency, but they are issued by two separate central banks and a banknote from one zone is not legal tender in the other, despite the identical name and nearly identical design.

Using someone else's currency outright

Ecuador replaced its own currency with the US dollar in 2000, after a banking collapse made the sucre worthless almost overnight. El Salvador did the same in 2001, and added Bitcoin as a second legal tender in 2021, becoming the first country to do either.

Panama is the oldest and strangest case. Its official currency, the balboa, is pegged one-to-one with the dollar and the two are used interchangeably — but Panama has never printed its own paper money. Only coins carry the balboa; every banknote in circulation is a US dollar bill.

None of these countries has a seat at the US Federal Reserve. Interest rates set in Washington for American conditions apply directly to their economies, with no local lever to offset them. It is full monetary dependence without even the limited voice a currency union provides.

Independent, but still not their own money

Liechtenstein is a fully sovereign state and has used the Swiss franc since a currency treaty with Switzerland in 1980, rather than issue one of its own. Kiribati, Tuvalu and Nauru use the Australian dollar. Palau, the Marshall Islands and Micronesia use the US dollar. All six are UN member states with their own governments, flags and foreign policy — just no central bank of their own, usually because a domestic currency would be too small and too thinly traded to be worth maintaining.

What happens when a currency fails

Zimbabwe is the clearest illustration of the alternative. Hyperinflation in the late 2000s destroyed the Zimbabwean dollar so completely that the country abandoned it altogether in 2009 and ran on foreign currencies, mostly the US dollar, for most of the following decade. It has since tried more than once to reintroduce a domestic currency, with mixed results — a reminder that a currency only works for as long as people trust it, and that trust, once broken at that scale, is slow to rebuild.

Currency, in other words, is one of the few things on a country's data sheet that is not really a fact about that country alone. The country quiz uses currency as one of its clues precisely because it groups countries in ways that borders and flags do not.