diff --git a/client/src/main/java/io/split/client/ApiKeyCounter.java b/client/src/main/java/io/split/client/ApiKeyCounter.java
new file mode 100644
index 000000000..8c39394dd
--- /dev/null
+++ b/client/src/main/java/io/split/client/ApiKeyCounter.java
@@ -0,0 +1,66 @@
+package io.split.client;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ConcurrentHashMultiset;
+import com.google.common.collect.Multiset;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ApiKeyCounter {
+
+    private static final Logger _log = LoggerFactory.getLogger(ApiKeyCounter.class);
+    private static final Multiset<String> USED_API_KEYS = ConcurrentHashMultiset.create();
+
+    private ApiKeyCounter() {}
+
+    public static ApiKeyCounter getApiKeyCounterInstance() {
+        return ApyKeyCounterHolder.INSTANCE;
+    }
+
+    //Inner class to provide instance of class
+    private static class ApyKeyCounterHolder
+    {
+        private static final ApiKeyCounter INSTANCE = new ApiKeyCounter();
+    }
+
+    public void add(String apiKey) {
+        String message;
+        if (USED_API_KEYS.contains(apiKey)) {
+            message = String.format("factory instantiation: You already have %s with this API Key. " +
+                            "We recommend keeping only one instance of the factory at all times (Singleton pattern) and reusing " +
+                            "it throughout your application.",
+                    USED_API_KEYS.count(apiKey) == 1 ? "1 factory" : String.format("%s factories", USED_API_KEYS.count(apiKey)));
+            _log.warn(message);
+        } else if (!USED_API_KEYS.isEmpty()) {
+             message = "factory instantiation: You already have an instance of the Split factory. " +
+                    "Make sure you definitely want this additional instance. We recommend keeping only one instance of " +
+                    "the factory at all times (Singleton pattern) and reusing it throughout your application.“";
+            _log.warn(message);
+        }
+        USED_API_KEYS.add(apiKey);
+    }
+
+    public void remove(String apiKey) {
+        USED_API_KEYS.remove(apiKey);
+    }
+
+    /**
+     * Just for test
+     * @param apiKey
+     * @return
+     */
+    @VisibleForTesting
+    boolean isApiKeyPresent(String apiKey) {
+        return USED_API_KEYS.contains(apiKey);
+    }
+
+    /**
+     * Just for test
+     * @param apiKey
+     * @return
+     */
+    @VisibleForTesting
+    int getCount(String apiKey) {
+        return USED_API_KEYS.count(apiKey);
+    }
+}
diff --git a/client/src/main/java/io/split/client/SplitFactoryImpl.java b/client/src/main/java/io/split/client/SplitFactoryImpl.java
index 12823fcde..c521e6bae 100644
--- a/client/src/main/java/io/split/client/SplitFactoryImpl.java
+++ b/client/src/main/java/io/split/client/SplitFactoryImpl.java
@@ -1,7 +1,5 @@
 package io.split.client;
 
-import com.google.common.collect.ConcurrentHashMultiset;
-import com.google.common.collect.Multiset;
 import io.split.client.impressions.AsynchronousImpressionListener;
 import io.split.client.impressions.ImpressionListener;
 import io.split.client.impressions.ImpressionsManagerImpl;
@@ -62,7 +60,6 @@ public class SplitFactoryImpl implements SplitFactory {
     private final static long SSE_CONNECT_TIMEOUT = 30000;
     private final static long SSE_SOCKET_TIMEOUT = 70000;
 
-    private static final Multiset<String> USED_API_TOKENS = ConcurrentHashMultiset.create();
     private static Random RANDOM = new Random();
 
     private final SplitClient _client;
@@ -70,23 +67,12 @@ public class SplitFactoryImpl implements SplitFactory {
     private final Runnable destroyer;
     private final String _apiToken;
     private boolean isTerminated = false;
+    private final ApiKeyCounter _apiKeyCounter;
 
     public SplitFactoryImpl(String apiToken, SplitClientConfig config) throws URISyntaxException {
         _apiToken = apiToken;
-
-        if (USED_API_TOKENS.contains(apiToken)) {
-            String message = String.format("factory instantiation: You already have %s with this API Key. " +
-                    "We recommend keeping only one instance of the factory at all times (Singleton pattern) and reusing " +
-                    "it throughout your application.",
-                    USED_API_TOKENS.count(apiToken) == 1 ? "1 factory" : String.format("%s factories", USED_API_TOKENS.count(apiToken)));
-            _log.warn(message);
-        } else if (!USED_API_TOKENS.isEmpty()) {
-            String message = "factory instantiation: You already have an instance of the Split factory. " +
-                    "Make sure you definitely want this additional instance. We recommend keeping only one instance of " +
-                    "the factory at all times (Singleton pattern) and reusing it throughout your application.“";
-            _log.warn(message);
-        }
-        USED_API_TOKENS.add(apiToken);
+        _apiKeyCounter = ApiKeyCounter.getApiKeyCounterInstance();
+        _apiKeyCounter.add(apiToken);
 
         if (config.blockUntilReady() == -1) {
             //BlockUntilReady not been set
@@ -214,7 +200,7 @@ public void destroy() {
         synchronized (SplitFactoryImpl.class) {
             if (!isTerminated) {
                 destroyer.run();
-                USED_API_TOKENS.remove(_apiToken);
+                _apiKeyCounter.remove(_apiToken);
                 isTerminated = true;
             }
         }
diff --git a/client/src/test/java/io/split/client/ApiKeyCounterTest.java b/client/src/test/java/io/split/client/ApiKeyCounterTest.java
new file mode 100644
index 000000000..c017127ce
--- /dev/null
+++ b/client/src/test/java/io/split/client/ApiKeyCounterTest.java
@@ -0,0 +1,50 @@
+package io.split.client;
+
+import junit.framework.TestCase;
+import org.junit.Test;
+
+public class ApiKeyCounterTest extends TestCase {
+
+    private static final String FIRST_KEY = "KEYNUMBER1";
+    private static final String SECOND_KEY = "KEYNUMBER2";
+
+    @Test
+    public void testAddingNewToken() {
+        ApiKeyCounter.getApiKeyCounterInstance().add(FIRST_KEY);
+        assertTrue(ApiKeyCounter.getApiKeyCounterInstance().isApiKeyPresent(FIRST_KEY));
+
+        ApiKeyCounter.getApiKeyCounterInstance().remove(FIRST_KEY);
+    }
+
+    @Test
+    public void testAddingExistingToken() {
+        ApiKeyCounter.getApiKeyCounterInstance().add(FIRST_KEY);
+        ApiKeyCounter.getApiKeyCounterInstance().add(FIRST_KEY);
+
+        assertTrue(ApiKeyCounter.getApiKeyCounterInstance().isApiKeyPresent(FIRST_KEY));
+        assertEquals(2, ApiKeyCounter.getApiKeyCounterInstance().getCount(FIRST_KEY));
+        ApiKeyCounter.getApiKeyCounterInstance().remove(FIRST_KEY);
+        ApiKeyCounter.getApiKeyCounterInstance().remove(FIRST_KEY);
+    }
+
+    @Test
+    public void testRemovingToken() {
+        ApiKeyCounter.getApiKeyCounterInstance().add(FIRST_KEY);
+        ApiKeyCounter.getApiKeyCounterInstance().remove(FIRST_KEY);
+
+        assertFalse(ApiKeyCounter.getApiKeyCounterInstance().isApiKeyPresent(FIRST_KEY));
+        assertEquals(0, ApiKeyCounter.getApiKeyCounterInstance().getCount(FIRST_KEY));
+    }
+
+    @Test
+    public void testAddingNonExistingToken() {
+        ApiKeyCounter.getApiKeyCounterInstance().add(FIRST_KEY);
+        ApiKeyCounter.getApiKeyCounterInstance().add(SECOND_KEY);
+
+        assertTrue(ApiKeyCounter.getApiKeyCounterInstance().isApiKeyPresent(FIRST_KEY));
+        assertEquals(1, ApiKeyCounter.getApiKeyCounterInstance().getCount(FIRST_KEY));
+        assertEquals(1, ApiKeyCounter.getApiKeyCounterInstance().getCount(SECOND_KEY));
+        ApiKeyCounter.getApiKeyCounterInstance().remove(FIRST_KEY);
+        ApiKeyCounter.getApiKeyCounterInstance().remove(SECOND_KEY);
+    }
+}