diff --git a/run-tests.js b/run-tests.js
index b5c9a56..1ec24d3 100644
--- a/run-tests.js
+++ b/run-tests.js
@@ -4,5 +4,7 @@ const { formatPrice } = require('./src/format-price');
 assert.strictEqual(formatPrice(1250), '$12.50');
 assert.strictEqual(formatPrice(1005), '$10.05');
 assert.strictEqual(formatPrice(999), '$9.99');
+assert.strictEqual(formatPrice(1005, { currency: 'EUR' }), '10,05 €');
+assert.strictEqual(formatPrice(1005, { currency: 'JPY' }), '¥1005');
 
 console.log('all price tests passed');
diff --git a/src/format-price.js b/src/format-price.js
index 86851d8..3b105ce 100644
--- a/src/format-price.js
+++ b/src/format-price.js
@@ -1,8 +1,11 @@
-// TODO: someday support all ISO currencies and locale-aware formatting.
-function formatPrice(cents) {
-  const dollars = Math.floor(cents / 100);
-  const rem = cents % 100;
-  return '$' + dollars + '.' + rem;
+const { getFormatter } = require('./formatters/registry');
+require('./formatters/builtin');
+
+const config = require('./config');
+
+function formatPrice(cents, options = {}) {
+  const currency = options.currency || config.currency;
+  return getFormatter(currency).format(cents, options);
 }
 
 module.exports = { formatPrice };
diff --git a/src/formatters/builtin.js b/src/formatters/builtin.js
new file mode 100644
index 0000000..d5dbe01
--- /dev/null
+++ b/src/formatters/builtin.js
@@ -0,0 +1,5 @@
+const { PriceFormatter, registerFormatter } = require('./registry');
+
+registerFormatter('USD', new PriceFormatter({ symbol: '$' }));
+registerFormatter('EUR', new PriceFormatter({ symbol: '€', symbolPosition: 'suffix', separator: ',' }));
+registerFormatter('JPY', new PriceFormatter({ symbol: '¥', decimals: 0 }));
diff --git a/src/formatters/registry.js b/src/formatters/registry.js
new file mode 100644
index 0000000..c7f37c9
--- /dev/null
+++ b/src/formatters/registry.js
@@ -0,0 +1,35 @@
+// Pluggable per-currency formatter registry. Third parties can register
+// additional currencies (and per-country tax display) without editing core.
+const formatters = new Map();
+
+class PriceFormatter {
+  constructor({ symbol, decimals = 2, symbolPosition = 'prefix', separator = '.' }) {
+    this.symbol = symbol;
+    this.decimals = decimals;
+    this.symbolPosition = symbolPosition;
+    this.separator = separator;
+  }
+
+  format(minorUnits) {
+    const factor = 10 ** this.decimals;
+    const major = Math.floor(minorUnits / factor);
+    const minor = String(minorUnits % factor).padStart(this.decimals, '0');
+    const amount = this.decimals ? `${major}${this.separator}${minor}` : String(major);
+    return this.symbolPosition === 'prefix' ? this.symbol + amount : `${amount} ${this.symbol}`;
+  }
+}
+
+function registerFormatter(code, formatter) {
+  if (!(formatter instanceof PriceFormatter)) {
+    throw new TypeError(`formatter for ${code} must extend PriceFormatter`);
+  }
+  formatters.set(code.toUpperCase(), formatter);
+}
+
+function getFormatter(code) {
+  const formatter = formatters.get(String(code).toUpperCase());
+  if (!formatter) throw new Error(`no price formatter registered for ${code}`);
+  return formatter;
+}
+
+module.exports = { PriceFormatter, registerFormatter, getFormatter };