diff --git a/lib/Controller/RoomController.php b/lib/Controller/RoomController.php
index 5df098257d7..4edb2d92623 100644
--- a/lib/Controller/RoomController.php
+++ b/lib/Controller/RoomController.php
@@ -2507,6 +2507,7 @@ public function directDialIn(string $phoneNumber, string $caller): DataResponse
 
 		$caller = trim($caller);
 		// TODO: Use later and get name from addressbook? $cleanedCaller = $this->phoneNumberUtil->convertToStandardFormat($caller);
+		$inBoundPhoneNumber = $this->phoneNumberUtil->convertToStandardFormat($caller);
 		$user = $this->userManager->get($entity->getActorId());
 		try {
 			$room = $this->roomService->createConversation(
@@ -2522,7 +2523,14 @@ public function directDialIn(string $phoneNumber, string $caller): DataResponse
 			return new DataResponse(null, Http::STATUS_INTERNAL_SERVER_ERROR);
 		}
 
-		$participant = $this->participantService->joinRoomAsNewGuest($this->roomService, $room, '', true, displayName: $caller);
+		$participant = $this->participantService->joinRoomAsNewGuest(
+			$this->roomService,
+			$room,
+			'',
+			true,
+			displayName: $caller,
+			phoneNumber: $inBoundPhoneNumber,
+		);
 		return new DataResponse($this->formatRoom($room, $participant));
 	}
 
diff --git a/lib/Service/ParticipantService.php b/lib/Service/ParticipantService.php
index c9a2af4f728..6efa7cbb81d 100644
--- a/lib/Service/ParticipantService.php
+++ b/lib/Service/ParticipantService.php
@@ -498,7 +498,7 @@ public function joinRoomAsFederatedUser(Room $room, string $actorType, string $a
 	 * @throws InvalidPasswordException
 	 * @throws UnauthorizedException
 	 */
-	public function joinRoomAsNewGuest(RoomService $roomService, Room $room, string $password, bool $passedPasswordProtection = false, ?Participant $previousParticipant = null, ?string $displayName = null): Participant {
+	public function joinRoomAsNewGuest(RoomService $roomService, Room $room, string $password, bool $passedPasswordProtection = false, ?Participant $previousParticipant = null, ?string $displayName = null, ?string $phoneNumber = null): Participant {
 		$event = new BeforeGuestJoinedRoomEvent($room, $password, $passedPasswordProtection);
 		$this->dispatcher->dispatchTyped($event);
 
@@ -531,6 +531,10 @@ public function joinRoomAsNewGuest(RoomService $roomService, Room $room, string
 			if ($displayName !== null && $displayName !== '') {
 				$attendee->setDisplayName($displayName);
 			}
+			if ($phoneNumber !== null && $phoneNumber !== '') {
+				$attendee->setPhoneNumber($phoneNumber);
+				$attendee->setActorType(Attendee::ACTOR_PHONES);
+			}
 
 			$this->attendeeMapper->insert($attendee);
 
diff --git a/lib/Service/PhoneNumberValidation.php b/lib/Service/PhoneNumberValidation.php
index c1ce47af600..2f44cbe83d7 100644
--- a/lib/Service/PhoneNumberValidation.php
+++ b/lib/Service/PhoneNumberValidation.php
@@ -23,9 +23,7 @@ public function __construct(
 	 * Validate input as a phone number
 	 *
 	 * - Local number: allow
-	 * - International number
-	 *      a. If valid, strip + and allow
-	 *      b. If invalid, throw
+	 * - International number: If invalid, throw
 	 * @throws \InvalidArgumentException When the number is invalid
 	 */
 	public function validateNumber(string $phoneNumber): string {
@@ -46,10 +44,6 @@ public function validateNumber(string $phoneNumber): string {
 			throw new \InvalidArgumentException();
 		}
 
-		if (str_starts_with($standardPhoneNumber, '+')) {
-			return substr($standardPhoneNumber, 1);
-		}
-
-		throw new \InvalidArgumentException();
+		return $standardPhoneNumber;
 	}
 }
diff --git a/lib/SetupCheck/SIPConfiguration.php b/lib/SetupCheck/SIPConfiguration.php
index 6a0611f88e4..c29b433a77e 100644
--- a/lib/SetupCheck/SIPConfiguration.php
+++ b/lib/SetupCheck/SIPConfiguration.php
@@ -48,9 +48,11 @@ public function run(): SetupResult {
 		$query->select('phone_number')
 			->from('talk_phone_numbers')
 			->where($query->expr()->like('phone_number', $query->createNamedParameter(
-				$this->connection->escapeLikeParameter('+') . '%'
-			)))
-			->orWhere($query->expr()->like('phone_number', $query->createNamedParameter(
+				// TODO: Temporary disabled while we migrate to leading `+` for international numbers
+				// TODO: Either to be deleted later or should complain for numbers without it
+				// 	$this->connection->escapeLikeParameter('+') . '%'
+				// )))
+				// ->orWhere($query->expr()->like('phone_number', $query->createNamedParameter(
 				$this->connection->escapeLikeParameter('0') . '%'
 			)));