diff --git a/app/controllers/api/v1/widget/labels_controller.rb b/app/controllers/api/v1/widget/labels_controller.rb
index c6435da4b..564fec8fc 100644
--- a/app/controllers/api/v1/widget/labels_controller.rb
+++ b/app/controllers/api/v1/widget/labels_controller.rb
@@ -1,6 +1,6 @@
 class Api::V1::Widget::LabelsController < Api::V1::Widget::BaseController
   def create
-    if conversation.present?
+    if conversation.present? && label_defined_in_account?
       conversation.label_list.add(permitted_params[:label])
       conversation.save!
     end
@@ -19,6 +19,11 @@ class Api::V1::Widget::LabelsController < Api::V1::Widget::BaseController
 
   private
 
+  def label_defined_in_account?
+    label = @account.labels.find_by(title: permitted_params[:label])
+    label.present?
+  end
+
   def permitted_params
     params.permit(:id, :label, :website_token)
   end
diff --git a/spec/controllers/api/v1/widget/labels_controller_spec.rb b/spec/controllers/api/v1/widget/labels_controller_spec.rb
index 13ee6f18e..bdd47f9c9 100644
--- a/spec/controllers/api/v1/widget/labels_controller_spec.rb
+++ b/spec/controllers/api/v1/widget/labels_controller_spec.rb
@@ -12,8 +12,24 @@ RSpec.describe '/api/v1/widget/labels', type: :request do
   describe 'POST /api/v1/widget/labels' do
     let(:params) { { website_token: web_widget.website_token, label: 'customer-support' } }
 
-    context 'with correct website token' do
-      it 'returns the list of labels' do
+    context 'with correct website token and undefined label' do
+      it 'does not add the label' do
+        post '/api/v1/widget/labels',
+             params: params,
+             headers: { 'X-Auth-Token' => token },
+             as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(conversation.reload.label_list.count).to eq 0
+      end
+    end
+
+    context 'with correct website token and a defined label' do
+      before do
+        account.labels.create(title: 'customer-support')
+      end
+
+      it 'add the label to the conversation' do
         post '/api/v1/widget/labels',
              params: params,
              headers: { 'X-Auth-Token' => token },