diff --git a/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseActivity.java b/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseActivity.java
index b1009808ccccb..fcc4ec1228390 100644
--- a/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseActivity.java
+++ b/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseActivity.java
@@ -31,9 +31,11 @@ import android.webkit.CookieManager;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.phone.slice.SlicePurchaseController;
 
 import java.net.URL;
+import java.util.Base64;
 
 /**
  * Activity that launches when the user clicks on the performance boost notification.
@@ -56,11 +58,17 @@ import java.net.URL;
 public class SlicePurchaseActivity extends Activity {
     private static final String TAG = "SlicePurchaseActivity";
 
+    private static final int CONTENTS_TYPE_UNSPECIFIED = 0;
+    private static final int CONTENTS_TYPE_JSON = 1;
+    private static final int CONTENTS_TYPE_XML = 2;
+
     @NonNull private WebView mWebView;
     @NonNull private Context mApplicationContext;
     @NonNull private Intent mIntent;
     @NonNull private URL mUrl;
     @TelephonyManager.PremiumCapability protected int mCapability;
+    @Nullable private String mUserData;
+    private int mContentsType;
     private boolean mIsUserTriggeredFinish;
 
     @Override
@@ -72,6 +80,7 @@ public class SlicePurchaseActivity extends Activity {
         mCapability = mIntent.getIntExtra(SlicePurchaseController.EXTRA_PREMIUM_CAPABILITY,
                 SlicePurchaseController.PREMIUM_CAPABILITY_INVALID);
         String url = mIntent.getStringExtra(SlicePurchaseController.EXTRA_PURCHASE_URL);
+        mUserData = mIntent.getStringExtra(SlicePurchaseController.EXTRA_USER_DATA);
         mApplicationContext = getApplicationContext();
         mIsUserTriggeredFinish = true;
         logd("onCreate: subId=" + subId + ", capability="
@@ -81,7 +90,17 @@ public class SlicePurchaseActivity extends Activity {
         SlicePurchaseBroadcastReceiver.cancelNotification(mApplicationContext, mCapability);
 
         // Verify purchase URL is valid
-        mUrl = SlicePurchaseBroadcastReceiver.getPurchaseUrl(url);
+        String contentsType = mIntent.getStringExtra(SlicePurchaseController.EXTRA_CONTENTS_TYPE);
+        mContentsType = CONTENTS_TYPE_UNSPECIFIED;
+        if (!TextUtils.isEmpty(contentsType)) {
+            if (contentsType.equals("json")) {
+                mContentsType = CONTENTS_TYPE_JSON;
+            } else if (contentsType.equals("xml")) {
+                mContentsType = CONTENTS_TYPE_XML;
+            }
+        }
+        mUrl = SlicePurchaseBroadcastReceiver.getPurchaseUrl(url, mUserData,
+                mContentsType == CONTENTS_TYPE_UNSPECIFIED);
         if (mUrl == null) {
             String error = "Unable to create a purchase URL.";
             loge(error);
@@ -95,6 +114,20 @@ public class SlicePurchaseActivity extends Activity {
             return;
         }
 
+        // Verify user data exists if contents type is specified
+        if (mContentsType != CONTENTS_TYPE_UNSPECIFIED && TextUtils.isEmpty(mUserData)) {
+            String error = "Contents type was specified but user data does not exist.";
+            loge(error);
+            Intent data = new Intent();
+            data.putExtra(SlicePurchaseController.EXTRA_FAILURE_CODE,
+                    SlicePurchaseController.FAILURE_CODE_NO_USER_DATA);
+            data.putExtra(SlicePurchaseController.EXTRA_FAILURE_REASON, error);
+            SlicePurchaseBroadcastReceiver.sendSlicePurchaseAppResponseWithData(mApplicationContext,
+                    mIntent, SlicePurchaseController.EXTRA_INTENT_CARRIER_ERROR, data);
+            finishAndRemoveTask();
+            return;
+        }
+
         // Verify intent is valid
         if (!SlicePurchaseBroadcastReceiver.isIntentValid(mIntent)) {
             loge("Not starting SlicePurchaseActivity with an invalid Intent: " + mIntent);
@@ -115,9 +148,7 @@ public class SlicePurchaseActivity extends Activity {
         }
 
         // Clear any cookies that might be persisted from previous sessions before loading WebView
-        CookieManager.getInstance().removeAllCookies(value -> {
-            setupWebView();
-        });
+        CookieManager.getInstance().removeAllCookies(value -> setupWebView());
     }
 
     protected void onPurchaseSuccessful() {
@@ -190,14 +221,46 @@ public class SlicePurchaseActivity extends Activity {
         // Display WebView
         setContentView(mWebView);
 
-        // Load the URL
-        String userData = mIntent.getStringExtra(SlicePurchaseController.EXTRA_USER_DATA);
-        if (TextUtils.isEmpty(userData)) {
-            logd("Starting WebView with url: " + mUrl.toString());
-            mWebView.loadUrl(mUrl.toString());
+        // Start the WebView
+        startWebView(mWebView, mUrl.toString(), mContentsType, mUserData);
+    }
+
+    /**
+     * Send the URL to the WebView as either a GET or POST request, based on the contents type:
+     * <ul>
+     *     <li>
+     *         CONTENTS_TYPE_UNSPECIFIED:
+     *         If the user data exists, append it to the purchase URL and load it as a GET request.
+     *         If the user data does not exist, load just the purchase URL as a GET request.
+     *     </li>
+     *     <li>
+     *         CONTENTS_TYPE_JSON or CONTENTS_TYPE_XML:
+     *         The user data must exist. Send the JSON or XML formatted user data in a POST request.
+     *         If the user data is encoded, it must be prefaced by {@code encodedValue=} and will be
+     *         encoded in Base64. Decode the user data and send it in the POST request.
+     *     </li>
+     * </ul>
+     * @param webView The WebView to start.
+     * @param url The URL to start the WebView with.
+     * @param contentsType The contents type of the userData.
+     * @param userData The user data to send with the GET or POST request, if it exists.
+     */
+    @VisibleForTesting
+    public static void startWebView(@NonNull WebView webView, @NonNull String url, int contentsType,
+            @Nullable String userData) {
+        if (contentsType == CONTENTS_TYPE_UNSPECIFIED) {
+            logd("Starting WebView GET with url: " + url);
+            webView.loadUrl(url);
         } else {
-            logd("Starting WebView with url: " + mUrl.toString() + ", userData=" + userData);
-            mWebView.postUrl(mUrl.toString(), userData.getBytes());
+            byte[] data = userData.getBytes();
+            String[] split = userData.split("encodedValue=");
+            if (split.length > 1) {
+                logd("Decoding encoded value: " + split[1]);
+                data = Base64.getDecoder().decode(split[1]);
+            }
+            logd("Starting WebView POST with url: " + url + ", contentsType: " + contentsType
+                    + ", data: " + new String(data));
+            webView.postUrl(url, data);
         }
     }
 
diff --git a/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiver.java b/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiver.java
index 23b976638eef7..9b33704cc8e7e 100644
--- a/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiver.java
+++ b/packages/CarrierDefaultApp/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiver.java
@@ -173,7 +173,9 @@ public class SlicePurchaseBroadcastReceiver extends BroadcastReceiver{
         }
 
         String purchaseUrl = intent.getStringExtra(SlicePurchaseController.EXTRA_PURCHASE_URL);
-        if (getPurchaseUrl(purchaseUrl) == null) {
+        String userData = intent.getStringExtra(SlicePurchaseController.EXTRA_USER_DATA);
+        String contentsType = intent.getStringExtra(SlicePurchaseController.EXTRA_CONTENTS_TYPE);
+        if (getPurchaseUrl(purchaseUrl, userData, TextUtils.isEmpty(contentsType)) == null) {
             loge("isIntentValid: invalid purchase URL: " + purchaseUrl);
             return false;
         }
@@ -194,13 +196,40 @@ public class SlicePurchaseBroadcastReceiver extends BroadcastReceiver{
                         SlicePurchaseController.EXTRA_INTENT_NOTIFICATION_SHOWN);
     }
 
+    /**
+     * Get the {@link URL} from the given purchase URL String and user data, if it is valid.
+     *
+     * @param purchaseUrl The purchase URL String to use to create the URL.
+     * @param userData The user data parameter from the entitlement server.
+     * @param shouldAppendUserData If this is {@code true} and the {@code userData} exists,
+     *        the {@code userData} should be appended to the {@code purchaseUrl} to create the URL.
+     *        If this is false, only the {@code purchaseUrl} should be used and the {@code userData}
+     *        will be sent as data to the POST request instead.
+     * @return The URL from the given purchase URL and user data or {@code null} if it is invalid.
+     */
+    @Nullable public static URL getPurchaseUrl(@Nullable String purchaseUrl,
+            @Nullable String userData, boolean shouldAppendUserData) {
+        if (purchaseUrl == null) {
+            return null;
+        }
+        // Only append user data if it exists, otherwise just return the purchase URL
+        if (!shouldAppendUserData || TextUtils.isEmpty(userData)) {
+            return getPurchaseUrl(purchaseUrl);
+        }
+        URL url = getPurchaseUrl(purchaseUrl + "?" + userData);
+        if (url == null) {
+            url = getPurchaseUrl(purchaseUrl);
+        }
+        return url;
+    }
+
     /**
      * Get the {@link URL} from the given purchase URL String, if it is valid.
      *
      * @param purchaseUrl The purchase URL String to use to create the URL.
      * @return The purchase URL from the given String or {@code null} if it is invalid.
      */
-    @Nullable public static URL getPurchaseUrl(@Nullable String purchaseUrl) {
+    @Nullable private static URL getPurchaseUrl(@Nullable String purchaseUrl) {
         if (!URLUtil.isValidUrl(purchaseUrl)) {
             return null;
         }
diff --git a/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseActivityTest.java b/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseActivityTest.java
index cc103fa98e654..1ec180beea819 100644
--- a/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseActivityTest.java
+++ b/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseActivityTest.java
@@ -21,6 +21,7 @@ import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
 import android.app.NotificationManager;
@@ -33,6 +34,7 @@ import android.telephony.CarrierConfigManager;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
 import android.test.ActivityUnitTestCase;
+import android.webkit.WebView;
 
 import androidx.test.platform.app.InstrumentationRegistry;
 import androidx.test.runner.AndroidJUnit4;
@@ -46,6 +48,8 @@ import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import java.util.Base64;
+
 @RunWith(AndroidJUnit4.class)
 public class SlicePurchaseActivityTest extends ActivityUnitTestCase<SlicePurchaseActivity> {
     private static final String CARRIER = "Some Carrier";
@@ -59,6 +63,7 @@ public class SlicePurchaseActivityTest extends ActivityUnitTestCase<SlicePurchas
     @Mock CarrierConfigManager mCarrierConfigManager;
     @Mock NotificationManager mNotificationManager;
     @Mock PersistableBundle mPersistableBundle;
+    @Mock WebView mWebView;
 
     private SlicePurchaseActivity mSlicePurchaseActivity;
     private Context mContext;
@@ -153,4 +158,23 @@ public class SlicePurchaseActivityTest extends ActivityUnitTestCase<SlicePurchas
         mSlicePurchaseActivity.onDismissFlow();
         verify(mRequestFailedIntent).send();
     }
+
+    @Test
+    public void testStartWebView() {
+        // unspecified contents type
+        SlicePurchaseActivity.startWebView(mWebView, URL, 0 /* CONTENTS_TYPE_UNSPECIFIED */, null);
+        verify(mWebView).loadUrl(eq(URL));
+
+        // specified contents type with user data
+        String userData = "userData";
+        byte[] userDataBytes = userData.getBytes();
+        SlicePurchaseActivity.startWebView(mWebView, URL, 1 /* CONTENTS_TYPE_JSON */, userData);
+        verify(mWebView).postUrl(eq(URL), eq(userDataBytes));
+
+        // specified contents type with encoded user data
+        byte[] encodedUserData = Base64.getEncoder().encode(userDataBytes);
+        userData = "encodedValue=" + new String(encodedUserData);
+        SlicePurchaseActivity.startWebView(mWebView, URL, 1 /* CONTENTS_TYPE_JSON */, userData);
+        verify(mWebView, times(2)).postUrl(eq(URL), eq(userDataBytes));
+    }
 }
diff --git a/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiverTest.java b/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiverTest.java
index 952789c56b2ea..61847b517c8d4 100644
--- a/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiverTest.java
+++ b/packages/CarrierDefaultApp/tests/unit/src/com/android/carrierdefaultapp/SlicePurchaseBroadcastReceiverTest.java
@@ -160,14 +160,35 @@ public class SlicePurchaseBroadcastReceiverTest {
                 "file:///android_asset/slice_store_test.html"
         };
 
+        // test invalid URLs
         for (String url : invalidUrls) {
-            URL purchaseUrl = SlicePurchaseBroadcastReceiver.getPurchaseUrl(url);
+            URL purchaseUrl = SlicePurchaseBroadcastReceiver.getPurchaseUrl(url, null, false);
             assertNull(purchaseUrl);
         }
 
+        // test asset URL
         assertEquals(SlicePurchaseController.SLICE_PURCHASE_TEST_FILE,
                 SlicePurchaseBroadcastReceiver.getPurchaseUrl(
-                        SlicePurchaseController.SLICE_PURCHASE_TEST_FILE).toString());
+                        SlicePurchaseController.SLICE_PURCHASE_TEST_FILE, null, false).toString());
+
+        // test normal URL
+        String validUrl = "http://www.google.com";
+        assertEquals(validUrl,
+                SlicePurchaseBroadcastReceiver.getPurchaseUrl(validUrl, null, false).toString());
+
+        // test normal URL with user data but no append
+        String userData = "encryptedUserData=data";
+        assertEquals(validUrl,
+                SlicePurchaseBroadcastReceiver.getPurchaseUrl(validUrl, userData, false)
+                        .toString());
+
+        // test normal URL with user data and append
+        assertEquals(validUrl + "?" + userData,
+                SlicePurchaseBroadcastReceiver.getPurchaseUrl(validUrl, userData, true).toString());
+
+        // test normal URL without user data and append
+        assertEquals(validUrl,
+                SlicePurchaseBroadcastReceiver.getPurchaseUrl(validUrl, null, true).toString());
     }
 
     @Test