diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 769d1a4e8bc71..3db7218663c18 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -10300,6 +10300,10 @@ public class TelephonyManager {
      * <p>Requires Permission:
      * {@link android.Manifest.permission#MODIFY_PHONE_STATE MODIFY_PHONE_STATE} or that the
      * calling app has carrier privileges (see {@link #hasCarrierPrivileges}).
+     *
+     * Note: with only carrier privileges, it is not allowed to switch from multi-sim
+     * to single-sim
+     *
      * @param numOfSims number of live SIMs we want to switch to
      * @throws android.os.RemoteException
      */