diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 53ef07e..df9884f 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -12853,15 +12853,31 @@
 
         Context context = getPhoneFromSubIdOrDefault(subId).getContext();
 
-        UserHandle userHandle = null;
-        final long identity = Binder.clearCallingIdentity();
-        try {
-            userHandle = TelephonyUtils.getSubscriptionUserHandle(context, subId);
-        } finally {
-            Binder.restoreCallingIdentity(identity);
+        if (mTelecomFeatureFlags.telecomMainUserInGetRespondMessageApp()){
+            UserHandle mainUser = null;
+            Context userContext = null;
+            final long identity = Binder.clearCallingIdentity();
+            try {
+                mainUser = mUserManager.getMainUser();
+                userContext = context.createContextAsUser(mainUser, 0);
+                Log.d(LOG_TAG, "getDefaultRespondViaMessageApplication: mainUser = " + mainUser);
+            } finally {
+                Binder.restoreCallingIdentity(identity);
+            }
+            return SmsApplication.getDefaultRespondViaMessageApplicationAsUser(userContext,
+                    updateIfNeeded, mainUser);
+        } else {
+            UserHandle userHandle = null;
+            final long identity = Binder.clearCallingIdentity();
+            try {
+                userHandle = TelephonyUtils.getSubscriptionUserHandle(context, subId);
+            } finally {
+                Binder.restoreCallingIdentity(identity);
+            }
+            return SmsApplication.getDefaultRespondViaMessageApplicationAsUser(context,
+                    updateIfNeeded, userHandle);
         }
-        return SmsApplication.getDefaultRespondViaMessageApplicationAsUser(context,
-                updateIfNeeded, userHandle);
+
     }
 
     /**
diff --git a/src/com/android/phone/settings/RadioInfo.java b/src/com/android/phone/settings/RadioInfo.java
index 8b004d9..26db4b3 100644
--- a/src/com/android/phone/settings/RadioInfo.java
+++ b/src/com/android/phone/settings/RadioInfo.java
@@ -362,6 +362,7 @@
     private int mPreferredNetworkTypeResult;
     private int mCellInfoRefreshRateIndex;
     private int mPhoneId = SubscriptionManager.INVALID_PHONE_INDEX;
+    private static final int DEFAULT_PHONE_ID = 0;
 
     private int mSubId = SubscriptionManager.INVALID_SUBSCRIPTION_ID;
 
@@ -584,7 +585,15 @@
             mPhone = getPhone(SubscriptionManager.getDefaultSubscriptionId());
         }
         mSubId = SubscriptionManager.getDefaultSubscriptionId();
-        mPhoneId = SubscriptionManager.getPhoneId(mSubId);
+        if (mPhone != null) {
+            mPhoneId = mPhone.getPhoneId();
+        } else {
+            mPhoneId = SubscriptionManager.getPhoneId(mSubId);
+        }
+        if (!SubscriptionManager.isValidPhoneId(mPhoneId)) {
+            mPhoneId = DEFAULT_PHONE_ID;
+        }
+
         mTelephonyManager = getSystemService(TelephonyManager.class)
                 .createForSubscriptionId(mSubId);
         mEuiccManager = getSystemService(EuiccManager.class);