diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9cf44a8
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+test:
+	go test -v -race ./...
\ No newline at end of file
diff --git a/currency.go b/currency.go
index 3a1f076..2a38d2c 100644
--- a/currency.go
+++ b/currency.go
@@ -15,8 +15,37 @@ type Currency struct {
 	Thousand    string
 }
 
+type Currencies map[string]*Currency
+
+// CurrencyByNumericCode returns the currency given the numeric code defined in ISO-4271.
+func (c Currencies) CurrencyByNumericCode(code string) *Currency {
+	for _, sc := range c {
+		if sc.NumericCode == code {
+			return sc
+		}
+	}
+
+	return nil
+}
+
+// CurrencyByCode returns the currency given the currency code defined as a constant.
+func (c Currencies) CurrencyByCode(code string) *Currency {
+	sc, ok := c[code]
+	if !ok {
+		return nil
+	}
+
+	return sc
+}
+
+// Add updates currencies list by adding a given Currency to it.
+func (c Currencies) Add(currency *Currency) Currencies {
+	c[currency.Code] = currency
+	return c
+}
+
 // currencies represents a collection of currency.
-var currencies = map[string]*Currency{
+var currencies = Currencies{
 	AED: {Decimal: ".", Thousand: ",", Code: AED, Fraction: 2, NumericCode: "784", Grapheme: ".\u062f.\u0625", Template: "1 $"},
 	AFN: {Decimal: ".", Thousand: ",", Code: AFN, Fraction: 2, NumericCode: "971", Grapheme: "\u060b", Template: "1 $"},
 	ALL: {Decimal: ".", Thousand: ",", Code: ALL, Fraction: 2, NumericCode: "008", Grapheme: "L", Template: "$1"},
@@ -190,7 +219,7 @@ var currencies = map[string]*Currency{
 
 // AddCurrency lets you insert or update currency in currencies list.
 func AddCurrency(code, Grapheme, Template, Decimal, Thousand string, Fraction int) *Currency {
-	currencies[code] = &Currency{
+	c := Currency{
 		Code:     code,
 		Grapheme: Grapheme,
 		Template: Template,
@@ -198,8 +227,8 @@ func AddCurrency(code, Grapheme, Template, Decimal, Thousand string, Fraction in
 		Thousand: Thousand,
 		Fraction: Fraction,
 	}
-
-	return currencies[code]
+	currencies.Add(&c)
+	return &c
 }
 
 func newCurrency(code string) *Currency {
@@ -208,7 +237,7 @@ func newCurrency(code string) *Currency {
 
 // GetCurrency returns the currency given the code.
 func GetCurrency(code string) *Currency {
-	return currencies[code]
+	return currencies.CurrencyByCode(code)
 }
 
 // Formatter returns currency formatter representing
diff --git a/currency_test.go b/currency_test.go
index 2d748d8..324ecd5 100644
--- a/currency_test.go
+++ b/currency_test.go
@@ -88,3 +88,52 @@ func TestCurrency_GetNonExistingCurrency(t *testing.T) {
 		t.Errorf("Unexpected currency returned %+v", currency)
 	}
 }
+
+func TestCurrencies(t *testing.T) {
+	const currencyFooCode = "FOO"
+	const currencyFooNumericCode = "1234"
+	curFoo := &Currency{
+		Code:        currencyFooCode,
+		NumericCode: currencyFooNumericCode,
+		Fraction:    10,
+		Grapheme:    "1",
+		Template:    "2",
+		Decimal:     "3",
+		Thousand:    "4",
+	}
+	var cs = Currencies{
+		currencyFooCode: curFoo,
+	}
+	const currencyBarCode = "BAR"
+	const currencyBarNumericCode = "4321"
+	curBar := &Currency{
+		Code:        currencyBarCode,
+		NumericCode: currencyBarNumericCode,
+		Fraction:    1,
+		Grapheme:    "2",
+		Template:    "3",
+		Decimal:     "4",
+		Thousand:    "5",
+	}
+	cs = cs.Add(curBar)
+
+	ac := cs.CurrencyByCode(currencyFooCode)
+	if !curFoo.equals(ac) {
+		t.Errorf("unexpected currency returned. expected: %v, got %v", curFoo, ac)
+	}
+
+	ac = cs.CurrencyByNumericCode(currencyFooNumericCode)
+	if !curFoo.equals(ac) {
+		t.Errorf("unexpected currency returned. expected: %v, got %v", curFoo, ac)
+	}
+
+	ac = cs.CurrencyByCode(currencyBarCode)
+	if !curBar.equals(ac) {
+		t.Errorf("unexpected currency returned. expected: %v, got %v", curBar, ac)
+	}
+
+	ac = cs.CurrencyByNumericCode(currencyBarNumericCode)
+	if !curBar.equals(ac) {
+		t.Errorf("unexpected currency returned. expected: %v, got %v", curBar, ac)
+	}
+}