diff --git a/schema/Entity.json b/schema/Entity.json
index f04c32cfaf9e58eacaef3af43ef89b3d2c0a2883..5f1736c8cce65529d544d6f8f7923c14b5c8ee4d 100644
--- a/schema/Entity.json
+++ b/schema/Entity.json
@@ -28,6 +28,9 @@
             "object"
           ]
         },
+        "unitCode": {
+          "$ref": "https://forge.etsi.org/rep/NGSI-LD/NGSI-LD/raw/master/schema/common.json#/definitions/unitCode"
+        },
         "observedAt": {
           "$ref": "https://forge.etsi.org/rep/NGSI-LD/NGSI-LD/raw/master/schema/common.json#/definitions/observedAt"
         },
diff --git a/schema/common.json b/schema/common.json
index 29ea54cab84e3e68e67e7bbfc86b961afe434e4d..d88375f50393c22818ecd005303750e1216b00fc 100644
--- a/schema/common.json
+++ b/schema/common.json
@@ -14,6 +14,9 @@
       "type": "string",
       "pattern": "^((\\d|[a-zA-Z]|_)+(:(\\d|[a-zA-Z]|_)+)?(#\\d+)?)$|^(@context)$"
     },
+    "unitCode": {
+      "type": "string"
+    },
     "observedAt": {
       "type": "string",
       "format": "date-time"