diff --git a/core/api/current.txt b/core/api/current.txt
index 32134fcf20262..2c095ebd34516 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -42360,6 +42360,7 @@ package android.telephony.ims {
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public void getRegistrationTransportType(@NonNull java.util.concurrent.Executor, @NonNull java.util.function.Consumer<java.lang.Integer>);
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public int getVoWiFiModeSetting();
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public boolean isAdvancedCallingSettingEnabled();
+    method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public boolean isCrossSimCallingEnabledByUser() throws android.telephony.ims.ImsException;
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public boolean isTtyOverVolteEnabled();
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public boolean isVoWiFiRoamingSettingEnabled();
     method @RequiresPermission(anyOf={"android.permission.READ_PRIVILEGED_PHONE_STATE", android.Manifest.permission.READ_PRECISE_PHONE_STATE}) public boolean isVoWiFiSettingEnabled();
diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 473a2808cd00a..370751c796da5 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -11089,6 +11089,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setUiccApplicationsEnabled(int, boolean);
     field @RequiresPermission(android.Manifest.permission.MANAGE_SUBSCRIPTION_PLANS) public static final String ACTION_SUBSCRIPTION_PLANS_CHANGED = "android.telephony.action.SUBSCRIPTION_PLANS_CHANGED";
     field @NonNull public static final android.net.Uri ADVANCED_CALLING_ENABLED_CONTENT_URI;
+    field @NonNull public static final android.net.Uri CROSS_SIM_ENABLED_CONTENT_URI;
     field @Deprecated public static final int PROFILE_CLASS_DEFAULT = -1; // 0xffffffff
     field public static final int PROFILE_CLASS_OPERATIONAL = 2; // 0x2
     field public static final int PROFILE_CLASS_PROVISIONING = 1; // 0x1
@@ -12278,6 +12279,7 @@ package android.telephony.ims {
     method @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public void isSupported(int, int, @NonNull java.util.concurrent.Executor, @NonNull java.util.function.Consumer<java.lang.Boolean>) throws android.telephony.ims.ImsException;
     method @Deprecated @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public void registerImsRegistrationCallback(@NonNull java.util.concurrent.Executor, @NonNull android.telephony.ims.ImsMmTelManager.RegistrationCallback) throws android.telephony.ims.ImsException;
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setAdvancedCallingSettingEnabled(boolean);
+    method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setCrossSimCallingEnabled(boolean) throws android.telephony.ims.ImsException;
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setRttCapabilitySetting(boolean);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setVoWiFiModeSetting(int);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void setVoWiFiNonPersistent(boolean, int);
diff --git a/telephony/java/android/telephony/SubscriptionManager.java b/telephony/java/android/telephony/SubscriptionManager.java
index 904232b54b8f5..d4c2bc9d9b8b4 100644
--- a/telephony/java/android/telephony/SubscriptionManager.java
+++ b/telephony/java/android/telephony/SubscriptionManager.java
@@ -372,6 +372,26 @@ public class SubscriptionManager {
     public static final Uri WFC_ROAMING_ENABLED_CONTENT_URI = Uri.withAppendedPath(
             CONTENT_URI, "wfc_roaming_enabled");
 
+    /**
+     * A content {@link Uri} used to receive updates on cross sim enabled user setting.
+     * <p>
+     * Use this {@link Uri} with a {@link ContentObserver} to be notified of changes to the
+     * subscription cross sim calling enabled
+     * {@link ImsMmTelManager#isCrossSimCallingEnabledByUser()}
+     * while your app is running. You can also use a {@link android.app.job.JobService}
+     * to ensure your app
+     * is notified of changes to the {@link Uri} even when it is not running.
+     * Note, however, that using a {@link android.app.job.JobService} does not guarantee timely
+     * delivery of updates to the {@link Uri}.
+     * To be notified of changes to a specific subId, append subId to the URI
+     * {@link Uri#withAppendedPath(Uri, String)}.
+     * @hide
+     */
+    @NonNull
+    @SystemApi
+    public static final Uri CROSS_SIM_ENABLED_CONTENT_URI = Uri.withAppendedPath(CONTENT_URI,
+            SimInfo.COLUMN_CROSS_SIM_CALLING_ENABLED);
+
     /**
      * TelephonyProvider unique key column name is the subscription id.
      * <P>Type: TEXT (String)</P>
diff --git a/telephony/java/android/telephony/ims/ImsMmTelManager.java b/telephony/java/android/telephony/ims/ImsMmTelManager.java
index 218875e347c73..fe443f8a410ee 100644
--- a/telephony/java/android/telephony/ims/ImsMmTelManager.java
+++ b/telephony/java/android/telephony/ims/ImsMmTelManager.java
@@ -978,6 +978,105 @@ public class ImsMmTelManager implements RegistrationManager {
         }
     }
 
+    /**
+     * This configuration is meaningful only on dual sim device.
+     * If enabled, this will result in the device setting up IMS of all other
+     * active subscriptions over the INTERNET APN of the primary default data subscription
+     * when any of those subscriptions are roaming or out of service and if wifi is not available
+     * for VoWifi. This feature will be disabled if
+     * {@link CarrierConfigManager#KEY_CARRIER_CROSS_SIM_IMS_AVAILABLE_BOOL} is set to false.
+     * <p>Following are the conditions in which system will try to register IMS over
+     * cross sim
+     * <ul>
+     *     <li>Wifi is not available, one SIM is roaming and the default data
+     *     SIM is in home network. Then roaming SIM IMS will be registered over INTERNET APN of the
+     *     default data subscription </li>
+     *     <li>Wifi is not available, one SIM is out of service and the default data
+     *     SIM is in home network. Then out of service SIM IMS will be registered over INTERNET
+     *     APN of the default data subscription </li>
+     * </ul>
+     * <p>This API requires one of the following:
+     * <ul>
+     *     <li>The caller holds the READ_PRECISE_PHONE_STATE permission.</li>
+     *     <li>If the caller is the device or profile owner, the caller holds the
+     *     {@link Manifest.permission#READ_PRECISE_PHONE_STATE} permission.</li>
+     *     <li>The caller has carrier privileges (see
+     *     {@link android.telephony.TelephonyManager#hasCarrierPrivileges}) on any
+     *     active subscription.</li>
+     * </ul>
+     * <p>The profile owner is an app that owns a managed profile on the device; for more details
+     * see <a href="https://developer.android.com/work/managed-profiles">Work profiles</a>.
+     * Access by profile owners is deprecated and will be removed in a future release.
+     *
+     * @throws ImsException if the IMS service associated with this subscription is not available or
+     * the IMS service is not available.
+     * @return true if the user's setting for Voice over Cross SIM is enabled and false if it is not
+     */
+    @SuppressAutoDoc // No support for device / profile owner or carrier privileges (b/72967236).
+    @RequiresPermission(anyOf = {
+            android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE,
+            android.Manifest.permission.READ_PRECISE_PHONE_STATE})
+    public boolean isCrossSimCallingEnabledByUser() throws ImsException {
+        ITelephony iTelephony = getITelephony();
+        if (iTelephony == null) {
+            throw new ImsException("Could not find Telephony Service.",
+                    ImsException.CODE_ERROR_SERVICE_UNAVAILABLE);
+        }
+
+        try {
+            return iTelephony.isCrossSimCallingEnabledByUser(mSubId);
+        } catch (ServiceSpecificException sse) {
+            throw new ImsException(sse.getMessage(), sse.errorCode);
+        } catch (RemoteException e) {
+            e.rethrowAsRuntimeException();
+        }
+        // Not reachable. Adding return to make compiler happy.
+        return false;
+    }
+
+    /**
+     * Sets the user's setting for whether or not Voice over Cross SIM is enabled.
+     * If enabled, this will result in the device setting up IMS of all other
+     * active subscriptions over the INTERNET APN of the primary default data subscription
+     * when any of those subscriptions are roaming or out of service and if wifi is not available
+     * for VoWifi. This feature will be disabled if
+     * {@link CarrierConfigManager#KEY_CARRIER_CROSS_SIM_IMS_AVAILABLE_BOOL} is set to false.
+     *
+     * <p>Following are the conditions in which system will try to register IMS over
+     * cross sim
+     * <ul>
+     *     <li>Wifi is not available, one SIM is roaming and the default data
+     *     SIM is in home network. Then roaming SIM IMS will be registered over INTERNET APN of the
+     *     default data subscription </li>
+     *     <li>Wifi is not available, one SIM is out of service and the default data
+     *     SIM is in home network. Then out of service SIM IMS will be registered over INTERNET
+     *     APN of the default data subscription </li>
+     * </ul>
+     * @throws ImsException if the IMS service associated with this subscription is not available or
+     * the IMS service is not available.
+     * @param isEnabled true if the user's setting for Voice over Cross SIM is enabled,
+     *                 false otherwise
+     * @see #isCrossSimCallingEnabledByUser()
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(Manifest.permission.MODIFY_PHONE_STATE)
+    public void setCrossSimCallingEnabled(boolean isEnabled) throws ImsException {
+        ITelephony iTelephony = getITelephony();
+        if (iTelephony == null) {
+            throw new ImsException("Could not find Telephony Service.",
+                    ImsException.CODE_ERROR_SERVICE_UNAVAILABLE);
+        }
+
+        try {
+            iTelephony.setCrossSimCallingEnabled(mSubId, isEnabled);
+        } catch (ServiceSpecificException sse) {
+            throw new ImsException(sse.getMessage(), sse.errorCode);
+        } catch (RemoteException e) {
+            e.rethrowAsRuntimeException();
+        }
+    }
+
     /**
      * Returns the user's voice over WiFi roaming setting associated with the current subscription.
      *
diff --git a/telephony/java/com/android/internal/telephony/ITelephony.aidl b/telephony/java/com/android/internal/telephony/ITelephony.aidl
index 74753ca1560a3..d6dbcb139b3a6 100644
--- a/telephony/java/com/android/internal/telephony/ITelephony.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephony.aidl
@@ -1963,6 +1963,16 @@ interface ITelephony {
      */
     void setVoWiFiSettingEnabled(int subId, boolean isEnabled);
 
+    /**
+     * return true if the user's setting for Voice over Cross SIM is enabled and false if it is not
+     */
+    boolean isCrossSimCallingEnabledByUser(int subId);
+
+    /**
+     * Sets the user's setting for whether or not Voice over Cross SIM is enabled.
+     */
+    void setCrossSimCallingEnabled(int subId, boolean isEnabled);
+
     /**
      * return true if the user's setting for Voice over WiFi while roaming is enabled.
      */