diff --git a/telephony/java/android/telephony/SmsManager.java b/telephony/java/android/telephony/SmsManager.java
index 09046a679c37d..63d427a6f3c4a 100644
--- a/telephony/java/android/telephony/SmsManager.java
+++ b/telephony/java/android/telephony/SmsManager.java
@@ -951,8 +951,7 @@ public final class SmsManager {
      * @return associated subscription id
      */
     public int getSubscriptionId() {
-        final int subId = (mSubId == DEFAULT_SUBSCRIPTION_ID)
-                ? getDefaultSmsSubscriptionId() : mSubId;
+        final int subId = getSubIdOrDefault();
         boolean isSmsSimPickActivityNeeded = false;
         final Context context = ActivityThread.currentApplication().getApplicationContext();
         try {
@@ -984,6 +983,17 @@ public final class SmsManager {
         return subId;
     }
 
+    /**
+     * @return the subscription ID associated with this {@link SmsManager} or the default set by the
+     * user if this instance was created using {@link SmsManager#getDefault}.
+     *
+     * If there is no default set by the user, this method returns
+     * {@link SubscriptionManager#INVALID_SUBSCRIPTION_ID}.
+     */
+    private int getSubIdOrDefault() {
+        return (mSubId == DEFAULT_SUBSCRIPTION_ID) ? getDefaultSmsSubscriptionId() : mSubId;
+    }
+
     /**
      * Returns the ISms service, or throws an UnsupportedOperationException if
      * the service does not exist.
@@ -1151,8 +1161,9 @@ public final class SmsManager {
         try {
             ISms iSms = getISmsService();
             if (iSms != null) {
-                success = iSms.enableCellBroadcastForSubscriber(
-                        getSubscriptionId(), messageIdentifier, ranType);
+                // If getSubIdOrDefault() returns INVALID, we will use the default phone internally.
+                success = iSms.enableCellBroadcastForSubscriber(getSubIdOrDefault(),
+                        messageIdentifier, ranType);
             }
         } catch (RemoteException ex) {
             // ignore it
@@ -1187,8 +1198,9 @@ public final class SmsManager {
         try {
             ISms iSms = getISmsService();
             if (iSms != null) {
-                success = iSms.disableCellBroadcastForSubscriber(
-                        getSubscriptionId(), messageIdentifier, ranType);
+                // If getSubIdOrDefault() returns INVALID, we will use the default phone internally.
+                success = iSms.disableCellBroadcastForSubscriber(getSubIdOrDefault(),
+                        messageIdentifier, ranType);
             }
         } catch (RemoteException ex) {
             // ignore it
@@ -1230,7 +1242,8 @@ public final class SmsManager {
         try {
             ISms iSms = getISmsService();
             if (iSms != null) {
-                success = iSms.enableCellBroadcastRangeForSubscriber(getSubscriptionId(),
+                // If getSubIdOrDefault() returns INVALID, we will use the default phone internally.
+                success = iSms.enableCellBroadcastRangeForSubscriber(getSubIdOrDefault(),
                         startMessageId, endMessageId, ranType);
             }
         } catch (RemoteException ex) {
@@ -1273,7 +1286,8 @@ public final class SmsManager {
         try {
             ISms iSms = getISmsService();
             if (iSms != null) {
-                success = iSms.disableCellBroadcastRangeForSubscriber(getSubscriptionId(),
+                // If getSubIdOrDefault() returns INVALID, we will use the default phone internally.
+                success = iSms.disableCellBroadcastRangeForSubscriber(getSubIdOrDefault(),
                         startMessageId, endMessageId, ranType);
             }
         } catch (RemoteException ex) {