diff --git a/client/drivers/login_system.py b/client/drivers/login_system.py
index fee192f..b076ce7 100644
--- a/client/drivers/login_system.py
+++ b/client/drivers/login_system.py
@@ -17,12 +17,13 @@
 from models.pose_detection.frame_capturer import RaspCapturer
 
 NUM_FACES = 5
-QUIT = -4
+QUIT = -6
 RESET = -5
 BAD_STATUS_MESSAGES = {
     Status.NO_FACES.value: "No face detected please",
     Status.TOO_MANY_FACES.value: "Too many faces detected",
     Status.NO_MATCH.value: "Could not match face",
+    Status.ALREADY_REGISTERED.value: "Face already registered",
 }
 QUIT_INSTRUCTIONS = "Right button to quit"
 
diff --git a/client/models/face_recognition/recognition.py b/client/models/face_recognition/recognition.py
index 043f8a3..b322fbb 100644
--- a/client/models/face_recognition/recognition.py
+++ b/client/models/face_recognition/recognition.py
@@ -9,6 +9,7 @@
 
 
 class Status(Enum):
+    ALREADY_REGISTERED = -4
     NO_FACES = -3
     TOO_MANY_FACES = -2
     NO_MATCH = -1
@@ -72,6 +73,14 @@ def register_faces(user_id: int, faces: list[np.ndarray]) -> int:
     if not all(matches):
         return Status.TOO_MANY_FACES.value
 
+    # Ensure user is not already registered
+    for _, other_user_embeddings in iter_face_embeddings():
+        for embedding in face_embeddings:
+            matches = face_recognition.compare_faces(other_user_embeddings, embedding)
+
+            if any(matches):
+                return Status.ALREADY_REGISTERED.value
+
     register_face_embeddings(user_id, face_embeddings)
 
     return Status.OK.value