diff --git a/changelog.d/8217.bugfix b/changelog.d/8217.bugfix
new file mode 100644
index 0000000000..ecb7685d5c
--- /dev/null
+++ b/changelog.d/8217.bugfix
@@ -0,0 +1 @@
+Add user completion for matrix ids
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/members/RoomMemberQueryParams.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/members/RoomMemberQueryParams.kt
index dd83066dbb..2ccb7f7ba1 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/members/RoomMemberQueryParams.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/members/RoomMemberQueryParams.kt
@@ -30,7 +30,8 @@ data class RoomMemberQueryParams(
         val displayName: QueryStringValue,
         val memberships: List<Membership>,
         val userId: QueryStringValue,
-        val excludeSelf: Boolean
+        val excludeSelf: Boolean,
+        val displayNameOrUserId: QueryStringValue,
 ) {
 
     class Builder {
@@ -39,12 +40,14 @@ data class RoomMemberQueryParams(
         var displayName: QueryStringValue = QueryStringValue.IsNotEmpty
         var memberships: List<Membership> = Membership.all()
         var excludeSelf: Boolean = false
+        var displayNameOrUserId: QueryStringValue = QueryStringValue.NoCondition
 
         fun build() = RoomMemberQueryParams(
                 displayName = displayName,
                 memberships = memberships,
                 userId = userId,
-                excludeSelf = excludeSelf
+                excludeSelf = excludeSelf,
+                displayNameOrUserId = displayNameOrUserId
         )
     }
 }
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/membership/DefaultMembershipService.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/membership/DefaultMembershipService.kt
index 20708b3814..2b69821b60 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/membership/DefaultMembershipService.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/membership/DefaultMembershipService.kt
@@ -17,14 +17,13 @@
 package org.matrix.android.sdk.internal.session.room.membership
 
 import androidx.lifecycle.LiveData
-import com.otaliastudios.opengl.core.use
 import com.zhuinden.monarchy.Monarchy
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
 import io.realm.Realm
 import io.realm.RealmQuery
-import org.matrix.android.sdk.api.MatrixConfiguration
+import org.matrix.android.sdk.api.query.QueryStringValue
 import org.matrix.android.sdk.api.session.crypto.CryptoService
 import org.matrix.android.sdk.api.session.identity.ThreePid
 import org.matrix.android.sdk.api.session.room.members.MembershipService
@@ -58,7 +57,6 @@ internal class DefaultMembershipService @AssistedInject constructor(
         private val cryptoService: CryptoService,
         @UserId
         private val userId: String,
-        private val matrixConfiguration: MatrixConfiguration,
         private val queryStringValueProcessor: QueryStringValueProcessor
 ) : MembershipService {
 
@@ -120,6 +118,13 @@ internal class DefaultMembershipService @AssistedInject constructor(
                         if (queryParams.excludeSelf) {
                             notEqualTo(RoomMemberSummaryEntityFields.USER_ID, userId)
                         }
+                        if (queryParams.displayNameOrUserId != QueryStringValue.NoCondition) {
+                            beginGroup()
+                            process(RoomMemberSummaryEntityFields.USER_ID, queryParams.displayNameOrUserId)
+                            or()
+                            process(RoomMemberSummaryEntityFields.DISPLAY_NAME, queryParams.displayNameOrUserId)
+                            endGroup()
+                        }
                     }
         }
     }
diff --git a/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberController.kt b/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberController.kt
index 8552851254..d6f177da0e 100644
--- a/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberController.kt
+++ b/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberController.kt
@@ -76,6 +76,7 @@ class AutocompleteMemberController @Inject constructor(private val context: Cont
             roomMember.roomMemberSummary.let { user ->
                 id(user.userId)
                 matrixItem(user.toMatrixItem())
+                subName(user.userId)
                 avatarRenderer(host.avatarRenderer)
                 clickListener { host.listener?.onItemClick(roomMember) }
             }
diff --git a/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberPresenter.kt b/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberPresenter.kt
index ff04a4db17..0f337470f3 100644
--- a/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberPresenter.kt
+++ b/vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberPresenter.kt
@@ -112,8 +112,8 @@ class AutocompleteMemberPresenter @AssistedInject constructor(
      * ========================================================================================== */
 
     private fun createQueryParams(query: CharSequence?) = roomMemberQueryParams {
-        displayName = if (query.isNullOrBlank()) {
-            QueryStringValue.IsNotEmpty
+        displayNameOrUserId = if (query.isNullOrBlank()) {
+            QueryStringValue.NoCondition
         } else {
             QueryStringValue.Contains(query.toString(), QueryStringValue.Case.INSENSITIVE)
         }