diff --git a/libPhoneNumberShortNumber/NBShortNumberUtil.h b/libPhoneNumberShortNumber/NBShortNumberUtil.h
index 121c6a7..8208b3d 100644
--- a/libPhoneNumberShortNumber/NBShortNumberUtil.h
+++ b/libPhoneNumberShortNumber/NBShortNumberUtil.h
@@ -25,8 +25,10 @@ typedef NS_ENUM(NSUInteger, NBEShortNumberCost) {
 
 @property(nonatomic) NSDictionary<NSNumber *, NSArray<NSString *> *> *countryToRegionCodeMap;
 
-/// Initialize short number util with a default metadata helper.
-- (instancetype)init;
+/// Short number util singleton with a default metadata helper.
++ (NBShortNumberUtil *)sharedInstance;
+
+- (instancetype)init NS_UNAVAILABLE;
 
 /// Initialize short number util with a metadata helper.
 /// @param helper A metadata helper.
diff --git a/libPhoneNumberShortNumber/NBShortNumberUtil.m b/libPhoneNumberShortNumber/NBShortNumberUtil.m
index 270ab5b..33986a0 100644
--- a/libPhoneNumberShortNumber/NBShortNumberUtil.m
+++ b/libPhoneNumberShortNumber/NBShortNumberUtil.m
@@ -25,6 +25,17 @@ @implementation NBShortNumberUtil {
   NBPhoneNumberUtil *_phoneUtil;
 }
 
++ (NBShortNumberUtil *)sharedInstance {
+  static NBShortNumberUtil *sharedOnceInstance = nil;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    sharedOnceInstance =
+        [[self alloc] initWithMetadataHelper:[[NBShortNumberMetadataHelper alloc] init]
+                             phoneNumberUtil:[NBPhoneNumberUtil sharedInstance]];
+  });
+  return sharedOnceInstance;
+}
+
 - (instancetype)initWithMetadataHelper:(NBShortNumberMetadataHelper *)helper
                        phoneNumberUtil:(NBPhoneNumberUtil *)phoneNumberUtil {
   self = [super init];
@@ -36,11 +47,6 @@ - (instancetype)initWithMetadataHelper:(NBShortNumberMetadataHelper *)helper
   return self;
 }
 
-- (instancetype)init {
-  return [self initWithMetadataHelper:[[NBShortNumberMetadataHelper alloc] init]
-                      phoneNumberUtil:[NBPhoneNumberUtil sharedInstance]];
-}
-
 - (BOOL)isPossibleShortNumber:(NBPhoneNumber *)phoneNumber forRegion:(NSString *)regionDialingFrom {
   if (![self doesPhoneNumber:phoneNumber matchesRegion:regionDialingFrom]) {
     return NO;
diff --git a/libPhoneNumberShortNumber/README.md b/libPhoneNumberShortNumber/README.md
index 01ee934..39308a1 100644
--- a/libPhoneNumberShortNumber/README.md
+++ b/libPhoneNumberShortNumber/README.md
@@ -46,7 +46,7 @@ import libPhoneNumberShortNumber
 
 ## Usage - **NBShortNumberUtil**
 ```obj-c
-NBShortNumberUtil *shortNumberUtil = [[NBShortNumberUtil alloc] init];
+NBShortNumberUtil *shortNumberUtil = [NBShortNumberUtil sharedInstance];
     
     // possibleNumber                  : +33123456
     NSLog(@"Is possible short number: %d",