diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/MatrixConfiguration.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/MatrixConfiguration.kt
index c87f21d7ac..f8472319fd 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/MatrixConfiguration.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/MatrixConfiguration.kt
@@ -60,7 +60,11 @@ data class MatrixConfiguration(
         /**
          * RoomDisplayNameFallbackProvider to provide default room display name.
          */
-        val roomDisplayNameFallbackProvider: RoomDisplayNameFallbackProvider
+        val roomDisplayNameFallbackProvider: RoomDisplayNameFallbackProvider,
+        /**
+         * Thread messages default enable/disabled value
+         */
+        val threadMessagesEnabledDefault: Boolean = false,
 ) {
 
     /**
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/lightweight/LightweightSettingsStorage.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/lightweight/LightweightSettingsStorage.kt
index 700b94a985..65c98ab872 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/lightweight/LightweightSettingsStorage.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/lightweight/LightweightSettingsStorage.kt
@@ -19,6 +19,7 @@ package org.matrix.android.sdk.internal.database.lightweight
 import android.content.Context
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
+import org.matrix.android.sdk.api.MatrixConfiguration
 import javax.inject.Inject
 
 /**
@@ -27,7 +28,10 @@ import javax.inject.Inject
  * not for large data sets
  */
 
-class LightweightSettingsStorage  @Inject constructor(context: Context) {
+class LightweightSettingsStorage  @Inject constructor(
+        context: Context,
+        val matrixConfiguration: MatrixConfiguration
+) {
 
     private val sdkDefaultPrefs = PreferenceManager.getDefaultSharedPreferences(context.applicationContext)
 
@@ -38,7 +42,7 @@ class LightweightSettingsStorage  @Inject constructor(context: Context) {
     }
 
     fun areThreadMessagesEnabled(): Boolean {
-        return sdkDefaultPrefs.getBoolean(MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED, false)
+        return sdkDefaultPrefs.getBoolean(MATRIX_SDK_SETTINGS_THREAD_MESSAGES_ENABLED, matrixConfiguration.threadMessagesEnabledDefault)
     }
 
     companion object {
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/SyncResponseHandler.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/SyncResponseHandler.kt
index 1bbf54a788..ac3ae3df91 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/SyncResponseHandler.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/SyncResponseHandler.kt
@@ -75,7 +75,7 @@ internal class SyncResponseHandler @Inject constructor(
     suspend fun handleResponse(syncResponse: SyncResponse,
                                fromToken: String?,
                                reporter: ProgressReporter?) {
-        val isInitialSync = fromToken == null
+        var isInitialSync = fromToken == null
         Timber.v("Start handling sync, is InitialSync: $isInitialSync")
 
         measureTimeMillis {
diff --git a/vector-config/src/main/res/values/config-settings.xml b/vector-config/src/main/res/values/config-settings.xml
index 0121ee9ae7..40fc68bbae 100755
--- a/vector-config/src/main/res/values/config-settings.xml
+++ b/vector-config/src/main/res/values/config-settings.xml
@@ -36,8 +36,9 @@
     <!-- Level 1: Security and Privacy -->
 
     <!-- Level 1: Labs -->
+    <bool name="settings_labs_thread_messages_default">false</bool>
 
-    <!-- Level 1: Advcanced settings -->
+    <!-- Level 1: Advanced settings -->
 
     <!-- Level 1: Help and about -->
 
diff --git a/vector/src/main/java/im/vector/app/core/di/SingletonModule.kt b/vector/src/main/java/im/vector/app/core/di/SingletonModule.kt
index a5575ef536..211bc3987f 100644
--- a/vector/src/main/java/im/vector/app/core/di/SingletonModule.kt
+++ b/vector/src/main/java/im/vector/app/core/di/SingletonModule.kt
@@ -46,6 +46,7 @@ import im.vector.app.features.navigation.Navigator
 import im.vector.app.features.pin.PinCodeStore
 import im.vector.app.features.pin.SharedPrefPinCodeStore
 import im.vector.app.features.room.VectorRoomDisplayNameFallbackProvider
+import im.vector.app.features.settings.VectorPreferences
 import im.vector.app.features.ui.SharedPreferencesUiStateRepository
 import im.vector.app.features.ui.UiStateRepository
 import kotlinx.coroutines.CoroutineScope
@@ -113,10 +114,13 @@ object VectorStaticModule {
     }
 
     @Provides
-    fun providesMatrixConfiguration(vectorRoomDisplayNameFallbackProvider: VectorRoomDisplayNameFallbackProvider): MatrixConfiguration {
+    fun providesMatrixConfiguration(
+            vectorPreferences: VectorPreferences,
+            vectorRoomDisplayNameFallbackProvider: VectorRoomDisplayNameFallbackProvider): MatrixConfiguration {
         return MatrixConfiguration(
                 applicationFlavor = BuildConfig.FLAVOR_DESCRIPTION,
-                roomDisplayNameFallbackProvider = vectorRoomDisplayNameFallbackProvider
+                roomDisplayNameFallbackProvider = vectorRoomDisplayNameFallbackProvider,
+                threadMessagesEnabledDefault = vectorPreferences.areThreadMessagesEnabled()
         )
     }
 
diff --git a/vector/src/main/java/im/vector/app/features/MainActivity.kt b/vector/src/main/java/im/vector/app/features/MainActivity.kt
index 33b735551c..42bd2318b3 100644
--- a/vector/src/main/java/im/vector/app/features/MainActivity.kt
+++ b/vector/src/main/java/im/vector/app/features/MainActivity.kt
@@ -241,7 +241,7 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
                 // We have a session.
                 // Check it can be opened
                 if (sessionHolder.getActiveSession().isOpenable) {
-                    HomeActivity.newIntent(this)
+                    HomeActivity.newIntent(this, existingSession = true)
                 } else {
                     // The token is still invalid
                     navigator.softLogout(this)
diff --git a/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt b/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt
index 964fb6f365..1bd61c0f9e 100644
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt
@@ -90,6 +90,7 @@ import javax.inject.Inject
 data class HomeActivityArgs(
         val clearNotification: Boolean,
         val accountCreation: Boolean,
+        val existingSession: Boolean = false,
         val inviteNotificationRoomId: String? = null
 ) : Parcelable
 
@@ -253,6 +254,8 @@ class HomeActivity :
                 HomeActivityViewEvents.PromptToEnableSessionPush        -> handlePromptToEnablePush()
                 is HomeActivityViewEvents.OnCrossSignedInvalidated      -> handleCrossSigningInvalidated(it)
                 HomeActivityViewEvents.ShowAnalyticsOptIn               -> handleShowAnalyticsOptIn()
+                HomeActivityViewEvents.NotifyUserForThreadsMigration    -> handleNotifyUserForThreadsMigration()
+                is HomeActivityViewEvents.MigrateThreads                -> migrateThreadsIfNeeded(it.checkSession)
             }.exhaustive
         }
         homeActivityViewModel.onEach { renderState(it) }
@@ -269,6 +272,49 @@ class HomeActivity :
         navigator.openAnalyticsOptIn(this)
     }
 
+    /**
+     * Migrating from old threads io.element.thread to new m.thread needs an initial sync to
+     * sync and display existing messages appropriately
+     */
+    private fun migrateThreadsIfNeeded(checkSession: Boolean) {
+
+        if (checkSession) {
+            // We should check session to ensure we will only clear cache if needed
+            val args = intent.getParcelableExtra<HomeActivityArgs>(Mavericks.KEY_ARG)
+            if (args?.existingSession == true) {
+                // existingSession --> Will be true only if we came from an existing active session
+                Timber.i("----> Migrating threads from an existing session..")
+                handleThreadsMigration()
+            } else {
+                // We came from a new session and not an existing one,
+                // so there is no need to migrate threads while an initial synced performed
+                Timber.i("----> No thread migration needed, we are ok")
+                vectorPreferences.threadsMigrated()
+            }
+        } else {
+            // Proceed with migration
+            handleThreadsMigration()
+        }
+    }
+
+    /**
+     * Clear cache and restart to invoke an initial sync for threads migration
+     */
+    private fun handleThreadsMigration() {
+        Timber.i("----> Threads Migration detected, clearing cache and sync...")
+        vectorPreferences.threadsMigrated()
+        MainActivity.restartApp(this, MainActivityArgs(clearCache = true))
+    }
+
+    private fun handleNotifyUserForThreadsMigration() {
+        MaterialAlertDialogBuilder(this)
+                .setTitle("Threads, no longer experimental")
+                .setMessage("All \uD83C\uDF89 \uD83C\uDF89 threads created during experimental period will\n\n now be rendered as regular replies. This will be an one-off transition, as threads are now part of the matrix specification")
+                .setCancelable(true)
+                .setPositiveButton(R.string.ok) { _, _ -> }
+                .show()
+    }
+
     private fun handleIntent(intent: Intent?) {
         intent?.dataString?.let { deepLink ->
             val resolvedLink = when {
@@ -546,11 +592,13 @@ class HomeActivity :
         fun newIntent(context: Context,
                       clearNotification: Boolean = false,
                       accountCreation: Boolean = false,
+                      existingSession: Boolean = false,
                       inviteNotificationRoomId: String? = null
         ): Intent {
             val args = HomeActivityArgs(
                     clearNotification = clearNotification,
                     accountCreation = accountCreation,
+                    existingSession = existingSession,
                     inviteNotificationRoomId = inviteNotificationRoomId
             )
 
diff --git a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt
index adc44a57bd..e301967884 100644
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt
@@ -25,4 +25,7 @@ sealed interface HomeActivityViewEvents : VectorViewEvents {
     data class OnCrossSignedInvalidated(val userItem: MatrixItem.UserItem) : HomeActivityViewEvents
     object PromptToEnableSessionPush : HomeActivityViewEvents
     object ShowAnalyticsOptIn : HomeActivityViewEvents
+    object NotifyUserForThreadsMigration : HomeActivityViewEvents
+    data class MigrateThreads(val checkSession: Boolean) : HomeActivityViewEvents
+
 }
diff --git a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt
index 35c112b63a..bb248965e4 100644
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt
@@ -51,6 +51,7 @@ import org.matrix.android.sdk.api.util.toMatrixItem
 import org.matrix.android.sdk.flow.flow
 import org.matrix.android.sdk.internal.crypto.model.CryptoDeviceInfo
 import org.matrix.android.sdk.internal.crypto.model.MXUsersDevicesMap
+import org.matrix.android.sdk.internal.database.lightweight.LightweightSettingsStorage
 import org.matrix.android.sdk.internal.util.awaitCallback
 import timber.log.Timber
 import kotlin.coroutines.Continuation
@@ -62,6 +63,7 @@ class HomeActivityViewModel @AssistedInject constructor(
         private val activeSessionHolder: ActiveSessionHolder,
         private val reAuthHelper: ReAuthHelper,
         private val analyticsStore: AnalyticsStore,
+        private val lightweightSettingsStorage: LightweightSettingsStorage,
         private val vectorPreferences: VectorPreferences
 ) : VectorViewModel<HomeActivityViewState, HomeActivityViewActions, HomeActivityViewEvents>(initialState) {
 
@@ -84,6 +86,7 @@ class HomeActivityViewModel @AssistedInject constructor(
         checkSessionPushIsOn()
         observeCrossSigningReset()
         observeAnalytics()
+        initThreadsMigration()
     }
 
     private fun observeAnalytics() {
@@ -130,6 +133,49 @@ class HomeActivityViewModel @AssistedInject constructor(
                 .launchIn(viewModelScope)
     }
 
+    /**
+     * Handle threads migration. The migration includes:
+     * - Notify users that had io.element.thread enabled from labs
+     * - Re-Enable m.thread to those users (that they had enabled labs threads)
+     * - Handle migration when threads are enabled by default
+     */
+    private fun initThreadsMigration() {
+
+        // Notify users
+        if (vectorPreferences.shouldNotifyUserAboutThreads() && vectorPreferences.areThreadMessagesEnabled()) {
+            Timber.i("----> Notify users about threads")
+            // Notify the user if needed that we migrated to support m.thread
+            // instead of io.element.thread so old thread messages will be displayed as normal timeline messages
+            _viewEvents.post(HomeActivityViewEvents.NotifyUserForThreadsMigration)
+            vectorPreferences.userNotifiedAboutThreads()
+            return
+        }
+
+        // Migrate users with enabled lab settings
+        if (vectorPreferences.shouldNotifyUserAboutThreads() && vectorPreferences.shouldMigrateThreads()) {
+            Timber.i("----> Migrate threads with enabled labs")
+            // If user had io.element.thread enabled then enable the new thread support,
+            // clear cache to sync messages appropriately
+            vectorPreferences.setThreadMessagesEnabled()
+            lightweightSettingsStorage.setThreadMessagesEnabled(vectorPreferences.areThreadMessagesEnabled())
+            // Clear Cache
+            _viewEvents.post(HomeActivityViewEvents.MigrateThreads(checkSession = false))
+            return
+        }
+        // Enable all users
+        // When we would to enable threads for all
+        // if(vectorPreferences.shouldMigrateThreads) -->
+        // vectorPreferences.setThreadMessagesEnabled() &&
+        // lightweightSettingsStorage.setThreadMessagesEnabled(vectorPreferences.areThreadMessagesEnabled())
+        if(vectorPreferences.shouldMigrateThreads() && vectorPreferences.areThreadMessagesEnabled()){
+            Timber.i("----> Try to migrate threads")
+            _viewEvents.post(HomeActivityViewEvents.MigrateThreads(checkSession = true))
+            return
+        }
+
+
+    }
+
     private fun observeInitialSync() {
         val session = activeSessionHolder.getSafeActiveSession() ?: return
 
diff --git a/vector/src/main/java/im/vector/app/features/settings/VectorPreferences.kt b/vector/src/main/java/im/vector/app/features/settings/VectorPreferences.kt
index 352c5768fb..d263dc1cbb 100755
--- a/vector/src/main/java/im/vector/app/features/settings/VectorPreferences.kt
+++ b/vector/src/main/java/im/vector/app/features/settings/VectorPreferences.kt
@@ -201,7 +201,13 @@ class VectorPreferences @Inject constructor(private val context: Context) {
         private const val TAKE_PHOTO_VIDEO_MODE = "TAKE_PHOTO_VIDEO_MODE"
 
         private const val SETTINGS_LABS_RENDER_LOCATIONS_IN_TIMELINE = "SETTINGS_LABS_RENDER_LOCATIONS_IN_TIMELINE"
-        const val SETTINGS_LABS_ENABLE_THREAD_MESSAGES = "SETTINGS_LABS_ENABLE_THREAD_MESSAGES"
+
+        // This key will be used to identify clients with the old thread support enabled io.element.thread
+        const val SETTINGS_LABS_ENABLE_THREAD_MESSAGES_OLD_CLIENTS = "SETTINGS_LABS_ENABLE_THREAD_MESSAGES"
+
+        // This key will be used to identify clients with the new thread support enabled m.thread
+        const val SETTINGS_LABS_ENABLE_THREAD_MESSAGES = "SETTINGS_LABS_ENABLE_THREAD_MESSAGES_FINAL"
+        const val SETTINGS_THREAD_MESSAGES_SYNCED = "SETTINGS_THREAD_MESSAGES_SYNCED"
 
         // Possible values for TAKE_PHOTO_VIDEO_MODE
         const val TAKE_PHOTO_VIDEO_MODE_ALWAYS_ASK = 0
@@ -1006,7 +1012,55 @@ class VectorPreferences @Inject constructor(private val context: Context) {
         return defaultPrefs.getBoolean(SETTINGS_LABS_RENDER_LOCATIONS_IN_TIMELINE, true)
     }
 
+    /**
+     * Indicates whether or not thread messages are enabled
+     */
     fun areThreadMessagesEnabled(): Boolean {
-        return defaultPrefs.getBoolean(SETTINGS_LABS_ENABLE_THREAD_MESSAGES, false)
+        return defaultPrefs.getBoolean(SETTINGS_LABS_ENABLE_THREAD_MESSAGES, getDefault(R.bool.settings_labs_thread_messages_default))
+    }
+
+    /**
+     * Manually sets thread messages enabled, useful for migrating users from io.element.thread
+     */
+    fun setThreadMessagesEnabled() {
+        defaultPrefs
+                .edit()
+                .putBoolean(SETTINGS_LABS_ENABLE_THREAD_MESSAGES, true)
+                .apply()
+    }
+    /**
+     * Indicates whether or not the user will be notified about the new thread support
+     * We should notify the user only if he had old thread support enabled
+     */
+    fun shouldNotifyUserAboutThreads(): Boolean {
+        return defaultPrefs.getBoolean(SETTINGS_LABS_ENABLE_THREAD_MESSAGES_OLD_CLIENTS, false)
+    }
+
+    /**
+     * Indicates that the user have been notified about threads migration
+     */
+    fun userNotifiedAboutThreads() {
+        defaultPrefs
+                .edit()
+                .putBoolean(SETTINGS_LABS_ENABLE_THREAD_MESSAGES_OLD_CLIENTS, false)
+                .apply()
+    }
+
+    /**
+     * Indicates whether or not we should clear cache for threads migration.
+     * Default value is true, for fresh installs and updates
+     */
+    fun shouldMigrateThreads(): Boolean {
+        return defaultPrefs.getBoolean(SETTINGS_THREAD_MESSAGES_SYNCED, true)
+    }
+
+    /**
+     * Indicates that there no longer threads migration needed
+     */
+    fun threadsMigrated() {
+        defaultPrefs
+                .edit()
+                .putBoolean(SETTINGS_THREAD_MESSAGES_SYNCED, false)
+                .apply()
     }
 }
diff --git a/vector/src/main/java/im/vector/app/features/settings/VectorSettingsLabsFragment.kt b/vector/src/main/java/im/vector/app/features/settings/VectorSettingsLabsFragment.kt
index 118e820f84..683c1e1dd2 100644
--- a/vector/src/main/java/im/vector/app/features/settings/VectorSettingsLabsFragment.kt
+++ b/vector/src/main/java/im/vector/app/features/settings/VectorSettingsLabsFragment.kt
@@ -42,6 +42,7 @@ class VectorSettingsLabsFragment @Inject constructor(
         // clear cache
         findPreference<VectorSwitchPreference>(VectorPreferences.SETTINGS_LABS_ENABLE_THREAD_MESSAGES)?.let {
             it.onPreferenceClickListener = Preference.OnPreferenceClickListener {
+                vectorPreferences.threadsMigrated() // Manual actions should disable the ato enable mechanism
                 lightweightSettingsStorage.setThreadMessagesEnabled(vectorPreferences.areThreadMessagesEnabled())
                 displayLoadingView()
                 MainActivity.restartApp(requireActivity(), MainActivityArgs(clearCache = true))
diff --git a/vector/src/main/res/xml/vector_settings_labs.xml b/vector/src/main/res/xml/vector_settings_labs.xml
index 73193edfd5..5144f6fe1f 100644
--- a/vector/src/main/res/xml/vector_settings_labs.xml
+++ b/vector/src/main/res/xml/vector_settings_labs.xml
@@ -52,8 +52,8 @@
     <!--</im.vector.app.core.preference.VectorPreferenceCategory>-->
 
     <im.vector.app.core.preference.VectorSwitchPreference
-        android:defaultValue="false"
-        android:key="SETTINGS_LABS_ENABLE_THREAD_MESSAGES"
+        android:defaultValue="@bool/settings_labs_thread_messages_default"
+        android:key="SETTINGS_LABS_ENABLE_THREAD_MESSAGES_FINAL"
         android:summary="@string/labs_enable_thread_messages_desc"
         android:title="@string/labs_enable_thread_messages" />