diff --git a/application/dashboard/models.py b/application/dashboard/models.py
index a5e1148..80f82d5 100644
--- a/application/dashboard/models.py
+++ b/application/dashboard/models.py
@@ -6,7 +6,7 @@ from application import db
 class Plate(db.Model):
     __abstract__ = True
     id = db.Column(db.Integer, primary_key=True)
-    plate = db.Column(db.String(40), nullable=False)
+    plate = db.Column(db.String(40), unique=True, nullable=False)
 
 
 class LoggedItem(Plate):