diff --git a/src/api/core/organizations.rs b/src/api/core/organizations.rs
index 82e24861..8a55329d 100644
--- a/src/api/core/organizations.rs
+++ b/src/api/core/organizations.rs
@@ -1755,7 +1755,7 @@ async fn get_groups(org_id: String, _headers: AdminHeaders, conn: DbConn) -> Jso
 struct GroupRequest {
     Name: String,
     AccessAll: Option<bool>,
-    ExternalId: String,
+    ExternalId: Option<String>,
     Collections: Vec<SelectionReadOnly>,
 }
 
@@ -1777,7 +1777,7 @@ impl GroupRequest {
 
         group.name = self.Name.clone();
         group.access_all = access_all_value;
-        group.external_id = self.ExternalId.clone();
+        group.set_external_id(self.ExternalId.clone());
 
         Ok(group)
     }
@@ -1882,7 +1882,7 @@ async fn add_update_group(mut group: Group, collections: Vec<SelectionReadOnly>,
         "OrganizationId": group.organizations_uuid,
         "Name": group.name,
         "AccessAll": group.access_all,
-        "ExternalId": group.external_id
+        "ExternalId": group.get_external_id()
     })))
 }
 
@@ -1904,7 +1904,7 @@ async fn get_group_details(_org_id: String, group_id: String, _headers: AdminHea
         "OrganizationId": group.organizations_uuid,
         "Name": group.name,
         "AccessAll": group.access_all,
-        "ExternalId": group.external_id,
+        "ExternalId": group.get_external_id(),
         "Collections": collections_groups
     })))
 }
diff --git a/src/db/models/group.rs b/src/db/models/group.rs
index 721b3f85..41d65615 100644
--- a/src/db/models/group.rs
+++ b/src/db/models/group.rs
@@ -10,7 +10,7 @@ db_object! {
         pub organizations_uuid: String,
         pub name: String,
         pub access_all: bool,
-        pub external_id: String,
+        external_id: Option<String>,
         pub creation_date: NaiveDateTime,
         pub revision_date: NaiveDateTime,
     }
@@ -36,18 +36,22 @@ db_object! {
 
 /// Local methods
 impl Group {
-    pub fn new(organizations_uuid: String, name: String, access_all: bool, external_id: String) -> Self {
+    pub fn new(organizations_uuid: String, name: String, access_all: bool, external_id: Option<String>) -> Self {
         let now = Utc::now().naive_utc();
 
-        Self {
+        let mut new_model = Self {
             uuid: crate::util::get_uuid(),
             organizations_uuid,
             name,
             access_all,
-            external_id,
+            external_id: None,
             creation_date: now,
             revision_date: now,
-        }
+        };
+
+        new_model.set_external_id(external_id);
+
+        new_model
     }
 
     pub fn to_json(&self) -> Value {
@@ -63,6 +67,25 @@ impl Group {
             "RevisionDate": format_date(&self.revision_date)
         })
     }
+
+    pub fn set_external_id(&mut self, external_id: Option<String>) {
+        //Check if external id is empty. We don't want to have
+        //empty strings in the database
+        match external_id {
+            Some(external_id) => {
+                if external_id.is_empty() {
+                    self.external_id = None;
+                } else {
+                    self.external_id = Some(external_id)
+                }
+            },
+            None => self.external_id = None
+        }
+    }
+
+    pub fn get_external_id(&self) -> Option<String> {
+        self.external_id.clone()
+    }
 }
 
 impl CollectionGroup {
diff --git a/src/db/schemas/mysql/schema.rs b/src/db/schemas/mysql/schema.rs
index 51875e11..514bc67a 100644
--- a/src/db/schemas/mysql/schema.rs
+++ b/src/db/schemas/mysql/schema.rs
@@ -226,7 +226,7 @@ table! {
         organizations_uuid -> Text,
         name -> Text,
         access_all -> Bool,
-        external_id -> Text,
+        external_id -> Nullable<Text>,
         creation_date -> Timestamp,
         revision_date -> Timestamp,
     }
diff --git a/src/db/schemas/postgresql/schema.rs b/src/db/schemas/postgresql/schema.rs
index b2874f5e..23f9af7e 100644
--- a/src/db/schemas/postgresql/schema.rs
+++ b/src/db/schemas/postgresql/schema.rs
@@ -226,7 +226,7 @@ table! {
         organizations_uuid -> Text,
         name -> Text,
         access_all -> Bool,
-        external_id -> Text,
+        external_id -> Nullable<Text>,
         creation_date -> Timestamp,
         revision_date -> Timestamp,
     }
diff --git a/src/db/schemas/sqlite/schema.rs b/src/db/schemas/sqlite/schema.rs
index b2874f5e..23f9af7e 100644
--- a/src/db/schemas/sqlite/schema.rs
+++ b/src/db/schemas/sqlite/schema.rs
@@ -226,7 +226,7 @@ table! {
         organizations_uuid -> Text,
         name -> Text,
         access_all -> Bool,
-        external_id -> Text,
+        external_id -> Nullable<Text>,
         creation_date -> Timestamp,
         revision_date -> Timestamp,
     }