diff --git a/src/components/MessageForm/index.jsx b/src/components/MessageForm/index.jsx
index 69c3c23f..cae5616f 100644
--- a/src/components/MessageForm/index.jsx
+++ b/src/components/MessageForm/index.jsx
@@ -10,11 +10,14 @@ import {
   getChatResponse,
   updateCurrentMessage,
 } from '../../data/thunks';
+import { useCourseUpgrade } from '../../hooks';
 import { usePromptExperimentDecision } from '../../experiments';
 
 import './MessageForm.scss';
 
 const MessageForm = ({ courseId, shouldAutofocus, unitId }) => {
+  const { upgradeable } = useCourseUpgrade();
+
   const { apiIsLoading, currentMessage, apiError } = useSelector(state => state.learningAssistant);
   const dispatch = useDispatch();
   const inputRef = useRef();
@@ -35,7 +38,7 @@ const MessageForm = ({ courseId, shouldAutofocus, unitId }) => {
     if (currentMessage) {
       dispatch(acknowledgeDisclosure(true));
       dispatch(addChatMessage('user', currentMessage, courseId, promptExperimentVariationKey));
-      dispatch(getChatResponse(courseId, unitId, promptExperimentVariationKey));
+      dispatch(getChatResponse(courseId, unitId, upgradeable, promptExperimentVariationKey));
     }
   };
 
diff --git a/src/components/MessageForm/index.test.jsx b/src/components/MessageForm/index.test.jsx
index 6c8dba2b..220bfbdf 100644
--- a/src/components/MessageForm/index.test.jsx
+++ b/src/components/MessageForm/index.test.jsx
@@ -12,9 +12,14 @@ import {
   getChatResponse,
   updateCurrentMessage,
 } from '../../data/thunks';
+import { useCourseUpgrade } from '../../hooks';
 
 import MessageForm from '.';
 
+jest.mock('../../hooks', () => ({
+  useCourseUpgrade: jest.fn(),
+}));
+
 jest.mock('../../utils/surveyMonkey', () => ({
   showControlSurvey: jest.fn(),
   showVariationSurvey: jest.fn(),
@@ -81,6 +86,9 @@ describe('<MessageForm />', () => {
   beforeEach(() => {
     jest.resetAllMocks();
     usePromptExperimentDecision.mockReturnValue([]);
+    useCourseUpgrade.mockReturnValue({
+      upgradeable: true,
+    });
   });
 
   describe('when rendered', () => {
@@ -137,7 +145,7 @@ describe('<MessageForm />', () => {
 
       expect(acknowledgeDisclosure).toHaveBeenCalledWith(true);
       expect(addChatMessage).toHaveBeenCalledWith('user', currentMessage, defaultProps.courseId, undefined);
-      expect(getChatResponse).toHaveBeenCalledWith(defaultProps.courseId, defaultProps.unitId, undefined);
+      expect(getChatResponse).toHaveBeenCalledWith(defaultProps.courseId, defaultProps.unitId, true, undefined);
       expect(mockDispatch).toHaveBeenCalledTimes(3);
     });
 
@@ -187,6 +195,7 @@ describe('<MessageForm />', () => {
       expect(getChatResponse).toHaveBeenCalledWith(
         defaultProps.courseId,
         defaultProps.unitId,
+        true,
         OPTIMIZELY_PROMPT_EXPERIMENT_VARIATION_KEYS.UPDATED_PROMPT,
       );
       expect(mockDispatch).toHaveBeenCalledTimes(3);
diff --git a/src/components/Sidebar/Sidebar.scss b/src/components/Sidebar/Sidebar.scss
index 7dfff12e..8d385146 100644
--- a/src/components/Sidebar/Sidebar.scss
+++ b/src/components/Sidebar/Sidebar.scss
@@ -31,6 +31,11 @@
       height: 30px;
     }
   }
+
+  .trial-header {
+    font-size: 0.9em;
+    background-color: #F49974;
+  }
 }
 
 .separator {
diff --git a/src/components/Sidebar/index.jsx b/src/components/Sidebar/index.jsx
index d9bc6497..5f6425d8 100644
--- a/src/components/Sidebar/index.jsx
+++ b/src/components/Sidebar/index.jsx
@@ -1,20 +1,21 @@
 import React, { useRef, useEffect } from 'react';
 import { useSelector } from 'react-redux';
 import PropTypes from 'prop-types';
+
 import {
   Icon,
   IconButton,
 } from '@openedx/paragon';
 import { Close } from '@openedx/paragon/icons';
 
-import { useCourseUpgrade } from '../../hooks';
 import showSurvey from '../../utils/surveyMonkey';
 
 import APIError from '../APIError';
 import ChatBox from '../ChatBox';
 import Disclosure from '../Disclosure';
-import UpgradePanel from '../UpgradePanel';
 import MessageForm from '../MessageForm';
+import UpgradePanel from '../UpgradePanel';
+import { useCourseUpgrade, useTrackEvent } from '../../hooks';
 import { ReactComponent as XpertLogo } from '../../assets/xpert-logo.svg';
 import './Sidebar.scss';
 
@@ -30,7 +31,11 @@ const Sidebar = ({
     messageList,
   } = useSelector(state => state.learningAssistant);
 
-  const { upgradeable, auditTrialExpired } = useCourseUpgrade();
+  const {
+    upgradeable, upgradeUrl, auditTrialExpired, auditTrialDaysRemaining,
+  } = useCourseUpgrade();
+
+  const { track } = useTrackEvent();
 
   const chatboxContainerRef = useRef(null);
 
@@ -80,11 +85,53 @@ const Sidebar = ({
     <MessageForm courseId={courseId} shouldAutofocus unitId={unitId} />
   );
 
+  const handleUpgradeLinkClick = () => {
+    track('edx.ui.lms.learning_assistant.days_remaining_banner_upgrade_click');
+  };
+
+  const getUpgradeLink = () => (
+    <a
+      onClick={handleUpgradeLinkClick}
+      target="_blank"
+      href={upgradeUrl}
+      rel="noreferrer"
+      data-testid="days_remaining_banner_upgrade_link"
+    >
+      Upgrade
+    </a>
+  );
+
+  const getDaysRemainingMessage = () => { // eslint-disable-line consistent-return
+    if (auditTrialDaysRemaining > 1) {
+      const intlRelativeTime = new Intl.RelativeTimeFormat({ style: 'long' });
+      return (
+        <div data-testid="days-remaining-message">
+          Your trial ends {intlRelativeTime.format(auditTrialDaysRemaining, 'day')}. {getUpgradeLink()} for full access to Xpert.
+        </div>
+      );
+    } if (auditTrialDaysRemaining === 1) {
+      return (
+        <div data-testid="trial-ends-today-message">
+          Your trial ends today! {getUpgradeLink()} for full access to Xpert.
+        </div>
+      );
+    }
+  };
+
   const getSidebar = () => (
-    <div className="h-100 d-flex flex-column justify-content-stretch" data-testid="sidebar-xpert">
+    <div
+      className="h-100 d-flex flex-column justify-content-stretch"
+      data-testid="sidebar-xpert"
+    >
       <div className="p-3 sidebar-header" data-testid="sidebar-xpert-header">
         <XpertLogo />
       </div>
+      {upgradeable
+        && (
+          <div className="p-3 trial-header" data-testid="get-days-remaining-message">
+            {getDaysRemainingMessage()}
+          </div>
+        )}
       <span className="separator" />
       <ChatBox
         chatboxContainerRef={chatboxContainerRef}
diff --git a/src/components/Sidebar/index.test.jsx b/src/components/Sidebar/index.test.jsx
index 5f40a144..2f6f5421 100644
--- a/src/components/Sidebar/index.test.jsx
+++ b/src/components/Sidebar/index.test.jsx
@@ -1,14 +1,21 @@
 import React from 'react';
-import { screen, act } from '@testing-library/react';
+import { fireEvent, screen, act } from '@testing-library/react';
 
 import { usePromptExperimentDecision } from '../../experiments';
+import {
+  useCourseUpgrade, useTrackEvent,
+} from '../../hooks';
 import { render as renderComponent } from '../../utils/utils.test';
 import { initialState } from '../../data/slice';
 import showSurvey from '../../utils/surveyMonkey';
-import { useCourseUpgrade, useTrackEvent } from '../../hooks';
 
 import Sidebar from '.';
 
+jest.mock('../../hooks', () => ({
+  useCourseUpgrade: jest.fn(),
+  useTrackEvent: jest.fn(),
+}));
+
 jest.mock('../../utils/surveyMonkey', () => jest.fn());
 
 jest.mock('@edx/frontend-platform/analytics', () => ({
@@ -34,11 +41,6 @@ jest.mock('../../experiments', () => ({
   usePromptExperimentDecision: jest.fn(),
 }));
 
-jest.mock('../../hooks', () => ({
-  useCourseUpgrade: jest.fn(),
-  useTrackEvent: jest.fn(),
-}));
-
 const defaultProps = {
   courseId: 'some-course-id',
   isOpen: true,
@@ -67,11 +69,12 @@ const render = async (props = {}, sliceState = {}) => {
 };
 
 describe('<Sidebar />', () => {
-  beforeEach(() => {
+  beforeEach(async () => {
     jest.resetAllMocks();
     useCourseUpgrade.mockReturnValue({ upgradeable: false });
-    useTrackEvent.mockReturnValue({ track: jest.fn() });
     usePromptExperimentDecision.mockReturnValue([]);
+    useCourseUpgrade.mockReturnValue([]);
+    useTrackEvent.mockReturnValue({ track: jest.fn() });
   });
 
   describe('when it\'s open', () => {
@@ -90,13 +93,57 @@ describe('<Sidebar />', () => {
       expect(screen.queryByTestId('sidebar-xpert')).toBeInTheDocument();
     });
 
-    it('should not render xpert if audit trial is expired', () => {
+    it('If auditTrialDaysRemaining > 1, show days remaining', () => {
       useCourseUpgrade.mockReturnValue({
         upgradeable: true,
-        auditTrialExpired: true,
+        upgradeUrl: 'https://mockurl.com',
+        auditTrialDaysRemaining: 2,
       });
-      render();
-      expect(screen.queryByTestId('sidebar-xpert')).not.toBeInTheDocument();
+      render(undefined, { disclosureAcknowledged: true });
+      expect(screen.queryByTestId('sidebar-xpert')).toBeInTheDocument();
+      expect(screen.queryByTestId('get-days-remaining-message')).toBeInTheDocument();
+      expect(screen.queryByTestId('days-remaining-message')).toBeInTheDocument();
+    });
+
+    it('If auditTrialDaysRemaining === 1, say final day', () => {
+      useCourseUpgrade.mockReturnValue({
+        upgradeable: true,
+        upgradeUrl: 'https://mockurl.com',
+        auditTrialDaysRemaining: 1,
+      });
+      render(undefined, { disclosureAcknowledged: true });
+      expect(screen.queryByTestId('sidebar-xpert')).toBeInTheDocument();
+      expect(screen.queryByTestId('get-days-remaining-message')).toBeInTheDocument();
+      expect(screen.queryByTestId('trial-ends-today')).not.toBeInTheDocument();
+    });
+
+    it('should call track event on click', () => {
+      useCourseUpgrade.mockReturnValue({
+        upgradeable: true,
+        upgradeUrl: 'https://mockurl.com',
+        auditTrialDaysRemaining: 1,
+      });
+      const mockedTrackEvent = jest.fn();
+      useTrackEvent.mockReturnValue({ track: mockedTrackEvent });
+
+      render(undefined, { disclosureAcknowledged: true });
+      const upgradeLink = screen.queryByTestId('days_remaining_banner_upgrade_link');
+      expect(mockedTrackEvent).not.toHaveBeenCalled();
+      fireEvent.click(upgradeLink);
+      expect(mockedTrackEvent).toHaveBeenCalledWith('edx.ui.lms.learning_assistant.days_remaining_banner_upgrade_click');
+    });
+
+    it('If auditTrialDaysRemaining < 1, do not show either of those', () => {
+      useCourseUpgrade.mockReturnValue({
+        upgradeable: true,
+        upgradeUrl: 'https://mockurl.com',
+        auditTrialDaysRemaining: 0,
+      });
+      render(undefined, { disclosureAcknowledged: true });
+      expect(screen.queryByTestId('sidebar-xpert')).toBeInTheDocument();
+      expect(screen.queryByTestId('get-days-remaining-message')).toBeInTheDocument();
+      expect(screen.queryByTestId('days-remaining-message')).not.toBeInTheDocument();
+      expect(screen.queryByTestId('trial-ends-today')).not.toBeInTheDocument();
     });
   });
 
diff --git a/src/data/thunks.js b/src/data/thunks.js
index 31d71844..ac069283 100644
--- a/src/data/thunks.js
+++ b/src/data/thunks.js
@@ -1,6 +1,7 @@
 import { sendTrackEvent } from '@edx/frontend-platform/analytics';
 import { getAuthenticatedUser } from '@edx/frontend-platform/auth';
 
+import { camelCaseObject } from '@edx/frontend-platform';
 import trackChatBotMessageOptimizely from '../utils/optimizelyExperiment';
 import {
   fetchChatResponse,
@@ -55,7 +56,7 @@ export function addChatMessage(role, content, courseId, promptExperimentVariatio
   };
 }
 
-export function getChatResponse(courseId, unitId, promptExperimentVariationKey = undefined) {
+export function getChatResponse(courseId, unitId, upgradeable, promptExperimentVariationKey = undefined) {
   return async (dispatch, getState) => {
     const { userId } = getAuthenticatedUser();
     const { messageList } = getState().learningAssistant;
@@ -68,6 +69,13 @@ export function getChatResponse(courseId, unitId, promptExperimentVariationKey =
       const customQueryParams = promptExperimentVariationKey ? { responseVariation: promptExperimentVariationKey } : {};
       const message = await fetchChatResponse(courseId, messageList, unitId, customQueryParams);
 
+      // Refresh chat summary only on the first message for an upgrade eligible user
+      // so we can tell if the user has just initiated an audit trial
+      if (messageList.length === 1 && upgradeable) {
+        // eslint-disable-next-line no-use-before-define
+        dispatch(getLearningAssistantChatSummary(courseId));
+      }
+
       dispatch(setApiIsLoading(false));
       dispatch(addChatMessage(message.role, message.content, courseId, promptExperimentVariationKey));
     } catch (error) {
@@ -129,11 +137,19 @@ export function getLearningAssistantChatSummary(courseId) {
       }
 
       // Audit Trial
-      const auditTrial = data.audit_trial;
-
-      // If returned audit trial data is not empty
-      if (Object.keys(auditTrial).length !== 0) {
-        dispatch(setAuditTrial(auditTrial));
+      const auditTrial = {
+        startDate: data.audit_trial.start_date,
+        expirationDate: data.audit_trial.expiration_date,
+      };
+
+      // Validate audit trial data & dates
+      const auditTrialDatesValid = !(
+        Number.isNaN(Date.parse(auditTrial.startDate))
+        || Number.isNaN(Date.parse(auditTrial.expirationDate))
+      );
+
+      if (Object.keys(auditTrial).length !== 0 && auditTrialDatesValid) {
+        dispatch(setAuditTrial(camelCaseObject(auditTrial)));
       }
 
       if (data.audit_trial_length_days) { dispatch(setAuditTrialLengthDays(data.audit_trial_length_days)); }
diff --git a/src/data/thunks.test.js b/src/data/thunks.test.js
index 6214cc3f..8692bd95 100644
--- a/src/data/thunks.test.js
+++ b/src/data/thunks.test.js
@@ -26,7 +26,8 @@ describe('Thunks unit tests', () => {
 
   describe('addChatMessage()', () => {
     const mockDate = new Date(2024, 1, 1);
-    beforeAll(() => {
+
+    beforeEach(async () => {
       jest.useFakeTimers('modern');
       jest.setSystemTime(mockDate);
     });
@@ -110,8 +111,8 @@ describe('Thunks unit tests', () => {
       expect(dispatch).toHaveBeenNthCalledWith(5, {
         type: 'learning-assistant/setAuditTrial',
         payload: {
-          start_date: '2024-12-02T14:59:16.148236Z',
-          expiration_date: '9999-12-16T14:59:16.148236Z',
+          startDate: '2024-12-02T14:59:16.148236Z',
+          expirationDate: '9999-12-16T14:59:16.148236Z',
         },
       });
 
@@ -158,8 +159,8 @@ describe('Thunks unit tests', () => {
       expect(dispatch).toHaveBeenNthCalledWith(3, {
         type: 'learning-assistant/setAuditTrial',
         payload: {
-          start_date: '2024-12-02T14:59:16.148236Z',
-          expiration_date: '9999-12-16T14:59:16.148236Z',
+          startDate: '2024-12-02T14:59:16.148236Z',
+          expirationDate: '9999-12-16T14:59:16.148236Z',
         },
       });
 
diff --git a/src/utils/optimizelyExperiment.js b/src/utils/optimizelyExperiment.js
index 1ca3e241..c9772a82 100644
--- a/src/utils/optimizelyExperiment.js
+++ b/src/utils/optimizelyExperiment.js
@@ -3,7 +3,7 @@ import { getOptimizely } from '../data/optimizely';
 const trackChatBotMessageOptimizely = (userId, userAttributes = {}) => {
   const optimizelyInstance = getOptimizely();
 
-  if (!optimizelyInstance) { return; }
+  if (!optimizelyInstance || Object.keys(optimizelyInstance).length === 0) { return; }
 
   optimizelyInstance.onReady().then(() => {
     optimizelyInstance.track('learning_assistant_chat_message', userId, userAttributes);