diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 4e7fc292f3214..42488259cf27e 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -10541,6 +10541,7 @@ package android.telephony {
     method @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public boolean matchesCurrentSimOperator(@NonNull String, int, @Nullable String);
     method public boolean needsOtaServiceProvisioning();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void notifyOtaEmergencyNumberDbInstalled();
+    method @RequiresPermission(android.Manifest.permission.REBOOT) public int prepareForUnattendedReboot();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean rebootRadio();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public void reportDefaultNetworkStatus(boolean);
     method @RequiresPermission(allOf={android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.MODIFY_PHONE_STATE}) public void requestCellInfoUpdate(@NonNull android.os.WorkSource, @NonNull java.util.concurrent.Executor, @NonNull android.telephony.TelephonyManager.CellInfoCallback);
@@ -10660,6 +10661,9 @@ package android.telephony {
     field public static final int NR_DUAL_CONNECTIVITY_DISABLE = 2; // 0x2
     field public static final int NR_DUAL_CONNECTIVITY_DISABLE_IMMEDIATE = 3; // 0x3
     field public static final int NR_DUAL_CONNECTIVITY_ENABLE = 1; // 0x1
+    field public static final int PREPARE_UNATTENDED_REBOOT_ERROR = 2; // 0x2
+    field public static final int PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED = 1; // 0x1
+    field public static final int PREPARE_UNATTENDED_REBOOT_SUCCESS = 0; // 0x0
     field public static final int RADIO_POWER_OFF = 0; // 0x0
     field public static final int RADIO_POWER_ON = 1; // 0x1
     field public static final int RADIO_POWER_UNAVAILABLE = 2; // 0x2
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 2e2ba69e82ba0..aeba82a8ad8d3 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -4443,4 +4443,7 @@
 
     <!-- Whether to select voice/data/sms preference without user confirmation -->
     <bool name="config_voice_data_sms_auto_fallback">false</bool>
+
+    <!-- Whether to allow the caching of the SIM PIN for verification after unattended reboot -->
+    <bool name="config_allow_pin_storage_for_unattended_reboot">true</bool>
 </resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 10766222faf94..713436d195cf9 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2612,6 +2612,7 @@
   <java-symbol type="bool" name="config_defaultWindowFeatureContextMenu" />
   <java-symbol type="bool" name="config_overrideRemoteViewsActivityTransition" />
   <java-symbol type="attr" name="colorProgressBackgroundNormal" />
+  <java-symbol type="bool" name="config_allow_pin_storage_for_unattended_reboot" />
 
   <java-symbol type="layout" name="simple_account_item" />
   <java-symbol type="string" name="prohibit_manual_network_selection_in_gobal_mode" />
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 23bca0139af6d..acde6f64b03b2 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -4157,6 +4157,21 @@ public class CarrierConfigManager {
     public static final String KEY_ALLOWED_INITIAL_ATTACH_APN_TYPES_STRING_ARRAY =
             "allowed_initial_attach_apn_types_string_array";
 
+    /**
+     * Boolean indicating whether the SIM PIN can be stored and verified
+     * seamlessly after an unattended reboot.
+     *
+     * The device configuration value {@code config_allow_pin_storage_for_unattended_reboot}
+     * ultimately controls whether this carrier configuration option is used.  Where
+     * {@code config_allow_pin_storage_for_unattended_reboot} is false, the value of the
+     * {@link #KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL} carrier configuration option is
+     * ignored.
+     *
+     * @hide
+     */
+    public static final String KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL =
+            "store_sim_pin_for_unattended_reboot_bool";
+
     /** The default value for every variable. */
     private final static PersistableBundle sDefaults;
 
@@ -4710,6 +4725,7 @@ public class CarrierConfigManager {
         sDefaults.putInt(KEY_DEFAULT_RTT_MODE_INT, 0);
         sDefaults.putStringArray(KEY_ALLOWED_INITIAL_ATTACH_APN_TYPES_STRING_ARRAY,
                 new String[]{"ia", "default", "ims", "mms", "dun", "emergency"});
+        sDefaults.putBoolean(KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL, true);
     }
 
     /**
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index e8ace34793db6..30c28f8317bf8 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -121,12 +121,10 @@ import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.Executor;
 import java.util.function.Consumer;
@@ -14824,4 +14822,66 @@ public class TelephonyManager {
             Log.e(TAG, "Error calling ITelephony#clearSignalStrengthUpdateRequest", e);
         }
     }
+
+    /**
+     * The unattended reboot was prepared successfully.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_SUCCESS = 0;
+
+    /**
+     * The unattended reboot was prepared, but the user will need to manually
+     * enter the PIN code of at least one SIM card present in the device.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED = 1;
+
+    /**
+     * The unattended reboot was not prepared due to generic error.
+     * @hide
+     */
+    @SystemApi
+    public static final int PREPARE_UNATTENDED_REBOOT_ERROR = 2;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = {"PREPARE_UNATTENDED_REBOOT_"},
+            value = {
+                    PREPARE_UNATTENDED_REBOOT_SUCCESS,
+                    PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED,
+                    PREPARE_UNATTENDED_REBOOT_ERROR
+            })
+    public @interface PrepareUnattendedRebootResult {}
+
+    /**
+     * Prepare TelephonyManager for an unattended reboot. The reboot is required to be done
+     * shortly (e.g. within 15 seconds) after the API is invoked.
+     *
+     * <p>Requires Permission:
+     *   {@link android.Manifest.permission#REBOOT}
+     *
+     * @return {@link #PREPARE_UNATTENDED_REBOOT_SUCCESS} in case of success.
+     * {@link #PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED} if the device contains
+     * at least one SIM card for which the user needs to manually enter the PIN
+     * code after the reboot. {@link #PREPARE_UNATTENDED_REBOOT_ERROR} in case
+     * of error.
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.REBOOT)
+    @PrepareUnattendedRebootResult
+    public int prepareForUnattendedReboot() {
+        try {
+            ITelephony service = getITelephony();
+            if (service != null) {
+                return service.prepareForUnattendedReboot();
+            }
+        } catch (RemoteException e) {
+            Log.e(TAG, "Telephony#prepareForUnattendedReboot RemoteException", e);
+            e.rethrowFromSystemServer();
+        }
+        return PREPARE_UNATTENDED_REBOOT_ERROR;
+    }
 }
diff --git a/telephony/java/com/android/internal/telephony/ITelephony.aidl b/telephony/java/com/android/internal/telephony/ITelephony.aidl
index 77d46f4c39cdd..e270b8dc3fe4a 100644
--- a/telephony/java/com/android/internal/telephony/ITelephony.aidl
+++ b/telephony/java/com/android/internal/telephony/ITelephony.aidl
@@ -2414,4 +2414,18 @@ interface ITelephony {
      */
     void clearSignalStrengthUpdateRequest(int subId, in SignalStrengthUpdateRequest request,
             String callingPackage);
+
+    /**
+     * Prepare TelephonyManager for an unattended reboot. The reboot is
+     * required to be done shortly after the API is invoked.
+     *
+     * Requires system privileges.
+     *
+     * @return {@link #PREPARE_UNATTENDED_REBOOT_SUCCESS} in case of success.
+     * {@link #PREPARE_UNATTENDED_REBOOT_PIN_REQUIRED} if the device contains
+     * at least one SIM card for which the user needs to manually enter the PIN
+     * code after the reboot. {@link #PREPARE_UNATTENDED_REBOOT_ERROR} in case
+     * of error.
+     */
+    int prepareForUnattendedReboot();
 }