diff --git a/src/actions/appInstance.js b/src/actions/appInstance.js
index c2fcf794..6265b763 100644
--- a/src/actions/appInstance.js
+++ b/src/actions/appInstance.js
@@ -28,6 +28,7 @@ const getAppInstance = async (
 
     if (appInstance) {
       callback({
+        appInstanceId: id,
         type: GET_APP_INSTANCE_SUCCEEDED,
         payload: appInstance,
       });
@@ -42,6 +43,7 @@ const getAppInstance = async (
         GET_APP_INSTANCE_CHANNEL,
         async (event, response) => {
           callback({
+            appInstanceId: id,
             type: GET_APP_INSTANCE_SUCCEEDED,
             payload: response,
           });
diff --git a/src/actions/appInstanceResource.js b/src/actions/appInstanceResource.js
index 24472644..741d9555 100644
--- a/src/actions/appInstanceResource.js
+++ b/src/actions/appInstanceResource.js
@@ -26,6 +26,8 @@ const getAppInstanceResources = async (
       GET_APP_INSTANCE_RESOURCES_CHANNEL,
       async (event, response) => {
         callback({
+          // have to include the appInstanceId to avoid broadcasting
+          appInstanceId,
           type: GET_APP_INSTANCE_RESOURCES_SUCCEEDED,
           payload: response,
         });
@@ -55,6 +57,8 @@ const postAppInstanceResource = async (
       POST_APP_INSTANCE_RESOURCE_CHANNEL,
       async (event, response) => {
         callback({
+          // have to include the appInstanceId to avoid broadcasting
+          appInstanceId,
           type: POST_APP_INSTANCE_RESOURCE_SUCCEEDED,
           payload: response,
         });
@@ -82,6 +86,7 @@ const patchAppInstanceResource = async (
       PATCH_APP_INSTANCE_RESOURCE_CHANNEL,
       async (event, response) => {
         callback({
+          appInstanceId,
           type: PATCH_APP_INSTANCE_RESOURCE_SUCCEEDED,
           payload: response,
         });
diff --git a/src/components/phase/PhaseApp.js b/src/components/phase/PhaseApp.js
index 1db0a8bd..cb954921 100644
--- a/src/components/phase/PhaseApp.js
+++ b/src/components/phase/PhaseApp.js
@@ -54,6 +54,17 @@ class PhaseApp extends Component {
   }
 
   postMessage = data => {
+    // get component app instance id
+    const { appInstance } = this.props;
+    const { id: componentAppInstanceId } = appInstance || {};
+    // get app instance id in message
+    const { appInstanceId: messageAppInstanceId } = data;
+
+    // only post message to intended app instance
+    if (componentAppInstanceId !== messageAppInstanceId) {
+      return;
+    }
+
     const message = JSON.stringify(data);
 
     if (this.iframe.contentWindow.postMessage) {