diff --git a/.github/storage/experiments.json b/.github/storage/experiments.json
index 296ddcf..48eff40 100644
--- a/.github/storage/experiments.json
+++ b/.github/storage/experiments.json
@@ -100,6 +100,17 @@
       "it"
     ]
   },
+  "login-status-advisory-callout": {
+    "complete": false,
+    "file": "en-US/subset/login_status_advisory_callout_2025.ftl",
+    "issue": "57",
+    "locales": [
+      "de",
+      "en-CA",
+      "en-GB",
+      "fr"
+    ]
+  },
   "microsurvey-addons-csat-2024": {
     "complete": true,
     "file": "en-US/subset/microsurvey_addons_csat_2024_2024.ftl",
diff --git a/en-CA/subset/login_status_advisory_callout_2025.ftl b/en-CA/subset/login_status_advisory_callout_2025.ftl
new file mode 100644
index 0000000..94dcb67
--- /dev/null
+++ b/en-CA/subset/login_status_advisory_callout_2025.ftl
@@ -0,0 +1,21 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+## Branch: treatment-a
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-a = You’re signed out. Click the account icon to sign in.
+
+## Branch: treatment-b
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-b = Start syncing your data. Click the account icon to sign in.
+
+## Branch: treatment-c
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-c = Sign in to sync
diff --git a/en-GB/subset/login_status_advisory_callout_2025.ftl b/en-GB/subset/login_status_advisory_callout_2025.ftl
new file mode 100644
index 0000000..94dcb67
--- /dev/null
+++ b/en-GB/subset/login_status_advisory_callout_2025.ftl
@@ -0,0 +1,21 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+## Branch: treatment-a
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-a = You’re signed out. Click the account icon to sign in.
+
+## Branch: treatment-b
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-b = Start syncing your data. Click the account icon to sign in.
+
+## Branch: treatment-c
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-c = Sign in to sync
diff --git a/en-US/subset/login_status_advisory_callout_2025.ftl b/en-US/subset/login_status_advisory_callout_2025.ftl
new file mode 100644
index 0000000..94dcb67
--- /dev/null
+++ b/en-US/subset/login_status_advisory_callout_2025.ftl
@@ -0,0 +1,21 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+## Branch: treatment-a
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-a = You’re signed out. Click the account icon to sign in.
+
+## Branch: treatment-b
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-b = Start syncing your data. Click the account icon to sign in.
+
+## Branch: treatment-c
+
+# The 'account icon' is the toolbar button with a 'profile' icon of a human head/shoulders.
+# It's for dealing with your Mozilla account. When hovering the icon, the tooltip says 'Account'.
+login-status-advisory-title-c = Sign in to sync
diff --git a/l10n.toml b/l10n.toml
index dd7a9f1..a8a385a 100644
--- a/l10n.toml
+++ b/l10n.toml
@@ -229,3 +229,13 @@ locales = [
         "fr",
         "it"
     ]
+
+[[paths]]
+    reference = "en-US/subset/login_status_advisory_callout_2025.ftl"
+    l10n = "{locale}/subset/login_status_advisory_callout_2025.ftl"
+    locales = [
+        "de",
+        "en-CA",
+        "en-GB",
+        "fr"
+    ]