diff --git a/ontology/docs/building_config.md b/ontology/docs/building_config.md
index b2e0b97a5..ad4fce29d 100644
--- a/ontology/docs/building_config.md
+++ b/ontology/docs/building_config.md
@@ -204,8 +204,8 @@ ENTITY-CODE:
     represents this entity.
 *   **Code:** The human readable identifier for the entity. This should
     be unique in document scope.
-*   **cloud_device_id:** the cloud device id from the cloud iot registry.
-    This field is mandatory when a translation exists.
+*   **cloud_device_id:** the numeric device id from cloud iot registry.
+    This field is mandatory when a translation exists. Must be a numeric string.
 *   **Connections:** Used to specify connections from other entities (sources)
     pointing to this entity, with connection types. Entities are keys and cannot
     be repeated. Values are one or more connections, specified as a single
diff --git a/tools/validators/instance_validator/tests/fake_instances/GOOD/bc_entity_with_id.yaml b/tools/validators/instance_validator/tests/fake_instances/GOOD/bc_entity_with_id.yaml
index d67bf5bef..4f3a8c5e0 100644
--- a/tools/validators/instance_validator/tests/fake_instances/GOOD/bc_entity_with_id.yaml
+++ b/tools/validators/instance_validator/tests/fake_instances/GOOD/bc_entity_with_id.yaml
@@ -17,7 +17,7 @@
 DMP_EDM-17-GUID:
   type: HVAC/DMP_EDM
   code: DMP_EDM-17
-  cloud_device_id: "1234567890123456"
+  cloud_device_id: "123456"
   translation:
     exhaust_air_damper_command:
       present_value: "points.exhaust_air_damper_command.present_value"
diff --git a/tools/validators/instance_validator/validate/entity_instance.py b/tools/validators/instance_validator/validate/entity_instance.py
index 67abcf1e8..e15f6cbe8 100644
--- a/tools/validators/instance_validator/validate/entity_instance.py
+++ b/tools/validators/instance_validator/validate/entity_instance.py
@@ -47,7 +47,7 @@
 )
 _UDMI_UNIT_FIELD_PATTERN = re.compile(_UDMI_UNIT_FIELD_REGEX)
 
-_DEVICE_NUMERIC_ID_REGEX = r'[0-9]{16}'
+_DEVICE_NUMERIC_ID_REGEX = r'[0-9]+'
 _DEVICE_NUMERIC_ID_PATTERN = re.compile(_DEVICE_NUMERIC_ID_REGEX)
 
 # Faciltities naming patterns