diff --git a/backend/internal/service/user_group_service.go b/backend/internal/service/user_group_service.go
index bc3d966..9b68af7 100644
--- a/backend/internal/service/user_group_service.go
+++ b/backend/internal/service/user_group_service.go
@@ -62,7 +62,10 @@ func (s *UserGroupService) Create(input dto.UserGroupCreateDto) (group model.Use
 	group = model.UserGroup{
 		FriendlyName: input.FriendlyName,
 		Name:         input.Name,
-		LdapID:       &input.LdapID,
+	}
+
+	if input.LdapID != "" {
+		group.LdapID = &input.LdapID
 	}
 
 	if err := s.db.Preload("Users").Create(&group).Error; err != nil {
diff --git a/backend/internal/service/user_service.go b/backend/internal/service/user_service.go
index 455b9d1..57343d8 100644
--- a/backend/internal/service/user_service.go
+++ b/backend/internal/service/user_service.go
@@ -66,8 +66,11 @@ func (s *UserService) CreateUser(input dto.UserCreateDto) (model.User, error) {
 		Email:     input.Email,
 		Username:  input.Username,
 		IsAdmin:   input.IsAdmin,
-		LdapID:    &input.LdapID,
 	}
+	if input.LdapID != "" {
+		user.LdapID = &input.LdapID
+	}
+
 	if err := s.db.Create(&user).Error; err != nil {
 		if errors.Is(err, gorm.ErrDuplicatedKey) {
 			return model.User{}, s.checkDuplicatedFields(user)
diff --git a/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.down.sql b/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.down.sql
new file mode 100644
index 0000000..be451ac
--- /dev/null
+++ b/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.down.sql
@@ -0,0 +1,2 @@
+UPDATE users SET ldap_id = '' WHERE ldap_id IS NULL;
+UPDATE user_groups SET ldap_id = '' WHERE ldap_id IS NULL;
\ No newline at end of file
diff --git a/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.up.sql b/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.up.sql
new file mode 100644
index 0000000..01fe893
--- /dev/null
+++ b/backend/resources/migrations/postgres/20250120102531_fix_empy_ldap_id_string.up.sql
@@ -0,0 +1,2 @@
+UPDATE users SET ldap_id = null WHERE ldap_id = '';
+UPDATE user_groups SET ldap_id = null WHERE ldap_id = '';
\ No newline at end of file
diff --git a/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.down.sql b/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.down.sql
new file mode 100644
index 0000000..be451ac
--- /dev/null
+++ b/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.down.sql
@@ -0,0 +1,2 @@
+UPDATE users SET ldap_id = '' WHERE ldap_id IS NULL;
+UPDATE user_groups SET ldap_id = '' WHERE ldap_id IS NULL;
\ No newline at end of file
diff --git a/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.up.sql b/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.up.sql
new file mode 100644
index 0000000..01fe893
--- /dev/null
+++ b/backend/resources/migrations/sqlite/20250120102531_fix_empy_ldap_id_string.up.sql
@@ -0,0 +1,2 @@
+UPDATE users SET ldap_id = null WHERE ldap_id = '';
+UPDATE user_groups SET ldap_id = null WHERE ldap_id = '';
\ No newline at end of file