diff --git a/static/js/licenseDialog.js b/static/js/licenseDialog.js
new file mode 100644
index 000000000..f9c8bf75a
--- /dev/null
+++ b/static/js/licenseDialog.js
@@ -0,0 +1,27 @@
+// vim: et:ts=4:sw=4:sts=4:ft=javascript
+'use strict';
+
+pandora.ui.licenseDialog = function() {
+
+    var that = pandora.ui.iconDialog({
+        buttons: [
+            Ox.Button({
+                id: 'close',
+                title: Ox._('Close')
+            })
+            .bindEvent({
+                click: function() {
+                    that.close();
+                }
+            })
+        ],
+        content: Ox._(
+            'This installation of <b>pan.do/ra</b> is unlicensed. '
+            + 'Please contact your vendor for more information on '
+            + 'how to acquire a license, or renew an expired one.'
+        ),
+        keys: {enter: 'close', escape: 'close'},
+        title: Ox._('License')
+    });
+
+};
diff --git a/static/js/pandora.js b/static/js/pandora.js
index a5c6df323..a5e1e4089 100644
--- a/static/js/pandora.js
+++ b/static/js/pandora.js
@@ -433,7 +433,8 @@ appPanel
         Ox.Fullscreen.bind('exit', pandora.UI.set);
         pandora.site.sectionButtonsWidth = pandora.$ui.sectionButtons.width() + 8;
         // allow site scripts to run after pandora is loaded
-        pandora.triggerEvent('loaded')
+        pandora.triggerEvent('loaded');
+        !pandora.isLicensed() && pandora.openLicenseDialog();
         loadUserScript && pandora.loadUserScript();
         document.removeEventListener && document.removeEventListener('keydown', onKeydown);
     }
diff --git a/static/js/utils.js b/static/js/utils.js
index b5dfac996..247dbea07 100644
--- a/static/js/utils.js
+++ b/static/js/utils.js
@@ -1954,6 +1954,10 @@ pandora.isEmbedURL = function(url) {
     return /^#embed(\?.*?)?$/.test(hash);
 };
 
+pandora.isLicensed = function() {
+    return pandora.site.license && pandora.site.license < +new Date();
+};
+
 pandora.isPrintURL = function(url) {
     url = url || document.location.href;
     var hash = Ox.parseURL(url).hash;
@@ -2015,6 +2019,22 @@ pandora.logEvent = function(data, event, element) {
     }
 };
 
+pandora.openLicenseDialog = function() {
+    if (!pandora.hasDialogOrScreen()) {
+        pandora.ui.licenseDialog().open().bindEvent({
+            close: function() {
+                setTimeout(function() {
+                    !pandora.isLicensed() && pandora.openLicenseDialog();
+                }, 900000); // 15 minutes
+            }
+        });
+    } else {
+        setTimeout(function() {
+            !pandora.isLicensed() && pandora.openLicenseDialog();
+        }, 60000); // 1 minute
+    }
+};
+
 pandora.openLink = function(url) {
     if (Ox.startsWith(url, 'mailto:')) {
         window.open(url);