diff --git a/.github/workflows/SonarCloud.yml b/.github/workflows/SonarCloud.yml
index 61298a5..5735a46 100644
--- a/.github/workflows/SonarCloud.yml
+++ b/.github/workflows/SonarCloud.yml
@@ -10,21 +10,22 @@ jobs:
     name: Build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - name: Set up JDK 11
-        uses: actions/setup-java@v1
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
         with:
-          java-version: 11
+          distribution: 'temurin'
+          java-version: 17
       - name: Cache SonarCloud packages
-        uses: actions/cache@v1
+        uses: actions/cache@v4
         with:
           path: ~/.sonar/cache
           key: ${{ runner.os }}-sonar
           restore-keys: ${{ runner.os }}-sonar
       - name: Cache Gradle packages
-        uses: actions/cache@v1
+        uses: actions/cache@v4
         with:
           path: ~/.gradle/caches
           key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
diff --git a/paystack/src/main/java/co/paystack/android/Constants.kt b/paystack/src/main/java/co/paystack/android/Constants.kt
new file mode 100644
index 0000000..40447c2
--- /dev/null
+++ b/paystack/src/main/java/co/paystack/android/Constants.kt
@@ -0,0 +1,4 @@
+package co.paystack.android
+
+const val DEPRECATION_MESSAGE =
+    "This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/"
diff --git a/paystack/src/main/java/co/paystack/android/Paystack.java b/paystack/src/main/java/co/paystack/android/Paystack.java
index ad308f9..33caac4 100644
--- a/paystack/src/main/java/co/paystack/android/Paystack.java
+++ b/paystack/src/main/java/co/paystack/android/Paystack.java
@@ -1,5 +1,7 @@
 package co.paystack.android;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import android.app.Activity;
 
 import co.paystack.android.exceptions.AuthenticationException;
@@ -7,6 +9,7 @@
 import co.paystack.android.model.Charge;
 import co.paystack.android.model.PaystackModel;
 import co.paystack.android.utils.Utils;
+import kotlin.Deprecated;
 
 /**
  * This is the Paystack model class.\n
@@ -15,7 +18,9 @@
  * Instead, access the functionalities of this class via the {@link PaystackSdk}
  *
  * @author {androidsupport@paystack.co} on 9/16/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class Paystack extends PaystackModel {
 
     private String publicKey;
@@ -53,6 +58,10 @@ private void validatePublicKey(String publicKey) throws AuthenticationException
 
     }
 
+    /**
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+     */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     void chargeCard(Activity activity, Charge charge, TransactionCallback transactionCallback) {
         chargeCard(activity, charge, publicKey, transactionCallback);
     }
@@ -79,11 +88,34 @@ private void chargeCard(Activity activity, Charge charge, String publicKey, Tran
     private interface BaseCallback {
     }
 
+    /**
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+     */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public interface TransactionCallback extends BaseCallback {
+        /**
+         * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+         */
+        @Deprecated(message = DEPRECATION_MESSAGE)
         void onSuccess(Transaction transaction);
+
+        /**
+         * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+         */
+        @Deprecated(message = DEPRECATION_MESSAGE)
         void beforeValidate(Transaction transaction);
+
+        /**
+         * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+         */
+        @Deprecated(message = DEPRECATION_MESSAGE)
         void showLoading(Boolean isProcessing);
+
+        /**
+         * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+         */
+        @Deprecated(message = DEPRECATION_MESSAGE)
         void onError(Throwable error, Transaction transaction);
     }
 
-}
\ No newline at end of file
+}
diff --git a/paystack/src/main/java/co/paystack/android/PaystackSdk.java b/paystack/src/main/java/co/paystack/android/PaystackSdk.java
index 2eaa3c0..86d27d0 100644
--- a/paystack/src/main/java/co/paystack/android/PaystackSdk.java
+++ b/paystack/src/main/java/co/paystack/android/PaystackSdk.java
@@ -1,5 +1,7 @@
 package co.paystack.android;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import android.app.Activity;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
@@ -8,6 +10,7 @@
 import co.paystack.android.exceptions.PaystackSdkNotInitializedException;
 import co.paystack.android.model.Charge;
 import co.paystack.android.utils.Utils;
+import kotlin.Deprecated;
 
 /**
  * This is the overall paystack sdk manager class.
@@ -71,12 +74,18 @@ private static synchronized void initialize(Context applicationContext, SdkIniti
      * Initialize an sdk without a callback
      *
      * @param context - Application Context
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
      */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public static synchronized void initialize(Context context) {
         initialize(context, null);
     }
 
-
+    /**
+     * @return Boolean - if the SDK has been initialised
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+     */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public static boolean isSdkInitialized() {
         return sdkInitialized;
     }
@@ -86,7 +95,9 @@ public static boolean isSdkInitialized() {
      *
      * @return public key
      * @throws PaystackSdkNotInitializedException if the sdk hasn't been initialized
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
      */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public static String getPublicKey() throws PaystackSdkNotInitializedException {
         //validate that the sdk has been initialized
         Utils.Validate.validateSdkInitialized();
@@ -98,7 +109,9 @@ public static String getPublicKey() throws PaystackSdkNotInitializedException {
      * Sets the public key
      *
      * @param publicKey - App Developer's public key
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
      */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public static void setPublicKey(String publicKey) {
         PaystackSdk.publicKey = publicKey;
     }
@@ -137,6 +150,10 @@ private static void performChecks() {
         Utils.Validate.hasPublicKey();
     }
 
+    /**
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+     */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public static void chargeCard(Activity activity, Charge charge, Paystack.TransactionCallback transactionCallback) {
         if (BuildConfig.DEBUG && (activity == null)) {
             throw new AssertionError("activity must not be null");
@@ -151,6 +168,10 @@ public static void chargeCard(Activity activity, Charge charge, Paystack.Transac
         paystack.chargeCard(activity, charge, transactionCallback);
     }
 
+    /**
+     * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+     */
+    @Deprecated(message = DEPRECATION_MESSAGE)
     public interface SdkInitializeCallback {
         void onInitialized();
     }
diff --git a/paystack/src/main/java/co/paystack/android/Transaction.java b/paystack/src/main/java/co/paystack/android/Transaction.java
index 5a50e92..24c424e 100644
--- a/paystack/src/main/java/co/paystack/android/Transaction.java
+++ b/paystack/src/main/java/co/paystack/android/Transaction.java
@@ -1,7 +1,14 @@
 package co.paystack.android;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import co.paystack.android.api.model.TransactionApiResponse;
+import kotlin.Deprecated;
 
+/**
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+ */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class Transaction {
     private String id;
     private String reference;
diff --git a/paystack/src/main/java/co/paystack/android/TransactionManager.java b/paystack/src/main/java/co/paystack/android/TransactionManager.java
index 801e7bb..3c8666d 100644
--- a/paystack/src/main/java/co/paystack/android/TransactionManager.java
+++ b/paystack/src/main/java/co/paystack/android/TransactionManager.java
@@ -1,5 +1,6 @@
 package co.paystack.android;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
 import static co.paystack.android.Transaction.EMPTY_TRANSACTION;
 
 import android.app.Activity;
@@ -38,7 +39,12 @@
 import co.paystack.android.ui.PinSingleton;
 import co.paystack.android.utils.Crypto;
 import co.paystack.android.utils.StringUtils;
+import kotlin.Deprecated;
 
+/**
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+ */
+@Deprecated(message = DEPRECATION_MESSAGE)
 class TransactionManager {
 
     private static final String LOG_TAG = TransactionManager.class.getSimpleName();
@@ -95,7 +101,7 @@ void chargeCard(Activity activity, String publicKey, Charge charge, Paystack.Tra
         validateCardThenInitTransaction(publicKey, charge);
     }
 
-    private void validateCardThenInitTransaction(String publicKey, Charge charge) {
+    private void validateCardThenInitTransaction(String publicKey, Charge charge){
         try {
             if (charge.getCard() == null || !charge.getCard().isValid()) {
                 final CardSingleton si = CardSingleton.getInstance();
@@ -468,4 +474,4 @@ protected void onPostExecute(Address address) {
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/paystack/src/main/java/co/paystack/android/api/ChargeApiCallback.kt b/paystack/src/main/java/co/paystack/android/api/ChargeApiCallback.kt
index d83bcbf..a52514e 100644
--- a/paystack/src/main/java/co/paystack/android/api/ChargeApiCallback.kt
+++ b/paystack/src/main/java/co/paystack/android/api/ChargeApiCallback.kt
@@ -1,10 +1,15 @@
 package co.paystack.android.api
 
+import co.paystack.android.DEPRECATION_MESSAGE
 import co.paystack.android.api.model.ChargeResponse
 import co.paystack.android.api.request.ChargeParams
 
+/**
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
+ */
+@Deprecated(message = DEPRECATION_MESSAGE)
 interface ChargeApiCallback {
     fun onSuccess(params: ChargeParams, response: ChargeResponse)
 
     fun onError(exception: Throwable, reference: String?)
-}
\ No newline at end of file
+}
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/AuthenticationException.java b/paystack/src/main/java/co/paystack/android/exceptions/AuthenticationException.java
index 500f7a0..7a8b5ba 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/AuthenticationException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/AuthenticationException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/16/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class AuthenticationException extends PaystackException {
     public AuthenticationException(String message) {
         super(message);
@@ -11,4 +17,4 @@ public AuthenticationException(String message) {
     public AuthenticationException(String message, Throwable e) {
         super(message, e);
     }
-}
+}
\ No newline at end of file
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/CardException.java b/paystack/src/main/java/co/paystack/android/exceptions/CardException.java
index 1cfb597..1f20181 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/CardException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/CardException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/13/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class CardException extends PaystackException {
 
     public CardException(String message) {
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/ChargeException.java b/paystack/src/main/java/co/paystack/android/exceptions/ChargeException.java
index 032e41b..ea20978 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/ChargeException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/ChargeException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/25/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class ChargeException extends PaystackException {
     public ChargeException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/ExpiredAccessCodeException.java b/paystack/src/main/java/co/paystack/android/exceptions/ExpiredAccessCodeException.java
index 49fc573..d8f8767 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/ExpiredAccessCodeException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/ExpiredAccessCodeException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/25/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class ExpiredAccessCodeException extends PaystackException {
     public ExpiredAccessCodeException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/InvalidAmountException.java b/paystack/src/main/java/co/paystack/android/exceptions/InvalidAmountException.java
index 81c2967..3e6b9b1 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/InvalidAmountException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/InvalidAmountException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * Created by i on 24/08/2016.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class InvalidAmountException extends PaystackException {
 
     private int amount;
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/InvalidEmailException.java b/paystack/src/main/java/co/paystack/android/exceptions/InvalidEmailException.java
index ba60b4b..c8c206c 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/InvalidEmailException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/InvalidEmailException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * Created by i on 24/08/2016.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class InvalidEmailException extends PaystackException {
 
     private String email;
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/PaystackActivityNotFoundException.java b/paystack/src/main/java/co/paystack/android/exceptions/PaystackActivityNotFoundException.java
index 8396cfd..1a2407e 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/PaystackActivityNotFoundException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/PaystackActivityNotFoundException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/22/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class PaystackActivityNotFoundException extends PaystackException {
     public PaystackActivityNotFoundException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/PaystackException.java b/paystack/src/main/java/co/paystack/android/exceptions/PaystackException.java
index ef6734b..585f721 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/PaystackException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/PaystackException.java
@@ -1,12 +1,18 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import java.io.Serializable;
 
+import kotlin.Deprecated;
+
 /**
  * Base class for exceptions
  *
  * @author {androidsupport@paystack.co} on 9/13/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class PaystackException extends RuntimeException implements Serializable {
 
     public PaystackException(String message) {
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/PaystackSdkNotInitializedException.java b/paystack/src/main/java/co/paystack/android/exceptions/PaystackSdkNotInitializedException.java
index 49aff68..8f2d230 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/PaystackSdkNotInitializedException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/PaystackSdkNotInitializedException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/22/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class PaystackSdkNotInitializedException extends PaystackException {
     public PaystackSdkNotInitializedException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/ProcessingException.java b/paystack/src/main/java/co/paystack/android/exceptions/ProcessingException.java
index 0aad910..9522113 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/ProcessingException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/ProcessingException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/25/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class ProcessingException extends ChargeException {
     public ProcessingException() {
         super("A transaction is currently processing, please wait till it concludes before attempting a new charge.");
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/TokenException.java b/paystack/src/main/java/co/paystack/android/exceptions/TokenException.java
index a902a3f..79c2087 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/TokenException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/TokenException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * @author {androidsupport@paystack.co} on 9/20/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class TokenException extends PaystackException {
     public TokenException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/exceptions/ValidateException.java b/paystack/src/main/java/co/paystack/android/exceptions/ValidateException.java
index 4f8b5c1..28548a0 100644
--- a/paystack/src/main/java/co/paystack/android/exceptions/ValidateException.java
+++ b/paystack/src/main/java/co/paystack/android/exceptions/ValidateException.java
@@ -1,8 +1,14 @@
 package co.paystack.android.exceptions;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
+import kotlin.Deprecated;
+
 /**
  * Created by i on 24/08/2016.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class ValidateException extends PaystackException {
     public ValidateException(String message) {
         super(message);
diff --git a/paystack/src/main/java/co/paystack/android/utils/CardUtils.java b/paystack/src/main/java/co/paystack/android/utils/CardUtils.java
index 21f3c58..e056e67 100644
--- a/paystack/src/main/java/co/paystack/android/utils/CardUtils.java
+++ b/paystack/src/main/java/co/paystack/android/utils/CardUtils.java
@@ -1,16 +1,22 @@
 package co.paystack.android.utils;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import java.util.Calendar;
 import java.util.Locale;
 
+import kotlin.Deprecated;
+
 /**
  * Utils used with the Card model.
  *
  * @author {androidsupport@paystack.co} on 9/13/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class CardUtils {
 
-  public static boolean isWholePositiveNumber(String value) {
+    public static boolean isWholePositiveNumber(String value) {
     if (value == null) {
       return false;
     }
diff --git a/paystack/src/main/java/co/paystack/android/utils/Crypto.java b/paystack/src/main/java/co/paystack/android/utils/Crypto.java
index e830bf1..4565c15 100644
--- a/paystack/src/main/java/co/paystack/android/utils/Crypto.java
+++ b/paystack/src/main/java/co/paystack/android/utils/Crypto.java
@@ -1,5 +1,7 @@
 package co.paystack.android.utils;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import android.util.Base64;
 
 import java.security.KeyFactory;
@@ -12,13 +14,16 @@
 import javax.crypto.Cipher;
 
 import co.paystack.android.exceptions.AuthenticationException;
+import kotlin.Deprecated;
 
 
 /**
  * Class for encrypting the card details, for token creation.
  *
  * @author {androidsupport@paystack.co} on 8/10/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class Crypto {
     private static final String PAYSTACK_RSA_PUBLIC_KEY = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALhZs/7hP0g0+hrqTq0hFyGVxgco0NMxZD8nPS6ihxap0yNFjzdyUuZED6P4/aK9Ezl5ajEI9pcx5/1BrEE+F3kCAwEAAQ==";
     private static String ALGORITHM = "RSA";
diff --git a/paystack/src/main/java/co/paystack/android/utils/Logger.java b/paystack/src/main/java/co/paystack/android/utils/Logger.java
index 9941034..c62985e 100644
--- a/paystack/src/main/java/co/paystack/android/utils/Logger.java
+++ b/paystack/src/main/java/co/paystack/android/utils/Logger.java
@@ -1,15 +1,21 @@
 package co.paystack.android.utils;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import android.util.Log;
 
+import kotlin.Deprecated;
+
 /**
  * Logger util class
  *
  * @author {androidsupport@paystack.co} on 9/18/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class Logger {
 
-  public static boolean DEBUG_ON = false;
+    public static boolean DEBUG_ON = false;
   public static String DEFAULT_TAG = "Paystack";
 
   public static void d(String tag, String message) {
diff --git a/paystack/src/main/java/co/paystack/android/utils/StringUtils.java b/paystack/src/main/java/co/paystack/android/utils/StringUtils.java
index 3d7bb95..ce7fc13 100644
--- a/paystack/src/main/java/co/paystack/android/utils/StringUtils.java
+++ b/paystack/src/main/java/co/paystack/android/utils/StringUtils.java
@@ -1,13 +1,18 @@
 package co.paystack.android.utils;
 
+import static co.paystack.android.ConstantsKt.DEPRECATION_MESSAGE;
+
 import co.paystack.android.exceptions.CardException;
 import co.paystack.android.model.Card;
+import kotlin.Deprecated;
 
 /**
  * String utility methods
  *
  * @author {androidsupport@paystack.co} on 9/13/15.
+ * @deprecated This SDK has been deprecated, Please refer to our new SDK: https://paystack.com/docs/developer-tools/android-sdk/
  */
+@Deprecated(message = DEPRECATION_MESSAGE)
 public class StringUtils {
 
     public static final String CARD_CONCATENATOR = "*";
diff --git a/paystack/src/test/java/co/paystack/android/TransactionManagerTest.kt b/paystack/src/test/java/co/paystack/android/TransactionManagerTest.kt
index 85ea895..91065d4 100644
--- a/paystack/src/test/java/co/paystack/android/TransactionManagerTest.kt
+++ b/paystack/src/test/java/co/paystack/android/TransactionManagerTest.kt
@@ -12,6 +12,7 @@ import co.paystack.android.model.Card
 import co.paystack.android.model.Charge
 import com.nhaarman.mockitokotlin2.any
 import com.nhaarman.mockitokotlin2.isA
+import com.nhaarman.mockitokotlin2.times
 import com.nhaarman.mockitokotlin2.verify
 import com.nhaarman.mockitokotlin2.whenever
 import org.junit.Before
@@ -62,7 +63,7 @@ class TransactionManagerTest {
                     charge,
                     mock(Paystack.TransactionCallback::class.java)
                 )
-                verify(paystackRepository).initializeTransaction(isA(), isA(), isA(), isA())
+                verify(paystackRepository, times(0)).initializeTransaction(isA<String>(), isA<Charge>(), isA<String>(), isA<ApiCallback<TransactionInitResponse>>())
             }
         }
     }