diff --git a/lib/actions/user.js b/lib/actions/user.js
index aa8e8d095..83d54036c 100644
--- a/lib/actions/user.js
+++ b/lib/actions/user.js
@@ -5,14 +5,16 @@ import { secureFetch } from '../util/middleware'
 import { isNewUser } from '../util/user'
 
 // Middleware API paths.
-const API_MONITORTRIP_PATH = '/api/secure/monitoredtrip'
+const API_MONITORED_TRIP_PATH = '/api/secure/monitoredtrip'
 const API_OTPUSER_PATH = '/api/secure/user'
-const API_OTPUSER_VERIFYSMS_PATH = '/verify_sms'
+const API_OTPUSER_VERIFY_SMS_SUBPATH = '/verify_sms'
 
 const setCurrentUser = createAction('SET_CURRENT_USER')
 const setCurrentUserMonitoredTrips = createAction('SET_CURRENT_USER_MONITORED_TRIPS')
 const setLastPhoneSmsRequest = createAction('SET_LAST_PHONE_SMS_REQUEST')
 export const setPathBeforeSignIn = createAction('SET_PATH_BEFORE_SIGNIN')
+export const clearItineraryExistence = createAction('CLEAR_ITINERARY_EXISTENCE')
+const setitineraryExistence = createAction('SET_ITINERARY_EXISTENCE')
 
 function createNewUser (auth0User) {
   return {
@@ -160,7 +162,7 @@ export function createOrUpdateUser (userData, silentOnSuccess = false) {
 export function fetchUserMonitoredTrips () {
   return async function (dispatch, getState) {
     const { accessToken, apiBaseUrl, apiKey } = getMiddlewareVariables(getState())
-    const requestUrl = `${apiBaseUrl}${API_MONITORTRIP_PATH}`
+    const requestUrl = `${apiBaseUrl}${API_MONITORED_TRIP_PATH}`
 
     const { data: trips, status } = await secureFetch(requestUrl, accessToken, apiKey, 'GET')
     if (status === 'success') {
@@ -182,10 +184,10 @@ export function createOrUpdateUserMonitoredTrip (tripData, isNew, silentOnSucces
 
     // Determine URL and method to use.
     if (isNew) {
-      requestUrl = `${apiBaseUrl}${API_MONITORTRIP_PATH}`
+      requestUrl = `${apiBaseUrl}${API_MONITORED_TRIP_PATH}`
       method = 'POST'
     } else {
-      requestUrl = `${apiBaseUrl}${API_MONITORTRIP_PATH}/${id}`
+      requestUrl = `${apiBaseUrl}${API_MONITORED_TRIP_PATH}/${id}`
       method = 'PUT'
     }
 
@@ -217,7 +219,7 @@ export function createOrUpdateUserMonitoredTrip (tripData, isNew, silentOnSucces
 export function deleteUserMonitoredTrip (tripId) {
   return async function (dispatch, getState) {
     const { accessToken, apiBaseUrl, apiKey } = getMiddlewareVariables(getState())
-    const requestUrl = `${apiBaseUrl}${API_MONITORTRIP_PATH}/${tripId}`
+    const requestUrl = `${apiBaseUrl}${API_MONITORED_TRIP_PATH}/${tripId}`
 
     const { message, status } = await secureFetch(requestUrl, accessToken, apiKey, 'DELETE')
     if (status === 'success') {
@@ -243,7 +245,7 @@ export function requestPhoneVerificationSms (newPhoneNumber) {
     // TODO: Should throttling be handled in the middleware?
     if (number !== newPhoneNumber || (now - timestamp) >= 60000) {
       const { accessToken, apiBaseUrl, apiKey, loggedInUser } = getMiddlewareVariables(state)
-      const requestUrl = `${apiBaseUrl}${API_OTPUSER_PATH}/${loggedInUser.id}${API_OTPUSER_VERIFYSMS_PATH}/${encodeURIComponent(newPhoneNumber)}`
+      const requestUrl = `${apiBaseUrl}${API_OTPUSER_PATH}/${loggedInUser.id}${API_OTPUSER_VERIFY_SMS_SUBPATH}/${encodeURIComponent(newPhoneNumber)}`
 
       const { message, status } = await secureFetch(requestUrl, accessToken, apiKey, 'GET')
 
@@ -273,7 +275,7 @@ export function requestPhoneVerificationSms (newPhoneNumber) {
 export function verifyPhoneNumber (code) {
   return async function (dispatch, getState) {
     const { accessToken, apiBaseUrl, apiKey, loggedInUser } = getMiddlewareVariables(getState())
-    const requestUrl = `${apiBaseUrl}${API_OTPUSER_PATH}/${loggedInUser.id}${API_OTPUSER_VERIFYSMS_PATH}/${code}`
+    const requestUrl = `${apiBaseUrl}${API_OTPUSER_PATH}/${loggedInUser.id}${API_OTPUSER_VERIFY_SMS_SUBPATH}/${code}`
 
     const { data, status } = await secureFetch(requestUrl, accessToken, apiKey, 'POST')
 
@@ -293,3 +295,26 @@ export function verifyPhoneNumber (code) {
     }
   }
 }
+
+/**
+ * Check itinerary existence for the given monitored trip.
+ */
+export function checkItineraryExistence (trip) {
+  return async function (dispatch, getState) {
+    const { accessToken, apiBaseUrl, apiKey } = getMiddlewareVariables(getState())
+    const requestUrl = `${apiBaseUrl}${API_MONITORED_TRIP_PATH}/checkitinerary`
+
+    // Empty state before performing the checks.
+    dispatch(clearItineraryExistence())
+
+    const { data, status } = await secureFetch(requestUrl, accessToken, apiKey, 'POST', {
+      body: JSON.stringify(trip)
+    })
+
+    if (status === 'success' && data) {
+      dispatch(setitineraryExistence(data))
+    } else {
+      alert('Error checking whether your selected trip is possible.')
+    }
+  }
+}
diff --git a/lib/components/narrative/narrative-itineraries.js b/lib/components/narrative/narrative-itineraries.js
index 93b245fa6..56c7f9ee0 100644
--- a/lib/components/narrative/narrative-itineraries.js
+++ b/lib/components/narrative/narrative-itineraries.js
@@ -38,7 +38,7 @@ class NarrativeItineraries extends Component {
   static propTypes = {
     itineraries: PropTypes.array,
     itineraryClass: PropTypes.func,
-    pending: PropTypes.number,
+    pending: PropTypes.bool,
     activeItinerary: PropTypes.number,
     setActiveItinerary: PropTypes.func,
     setActiveLeg: PropTypes.func,
diff --git a/lib/components/user/trip-basics-pane.js b/lib/components/user/trip-basics-pane.js
index 5b1bbaa25..928f7b697 100644
--- a/lib/components/user/trip-basics-pane.js
+++ b/lib/components/user/trip-basics-pane.js
@@ -1,27 +1,32 @@
 import { Field } from 'formik'
-import React from 'react'
+import React, { Component } from 'react'
 import {
   ControlLabel,
   FormControl,
   FormGroup,
-  HelpBlock
+  Glyphicon,
+  HelpBlock,
+  ProgressBar
 } from 'react-bootstrap'
+import { connect } from 'react-redux'
 import styled from 'styled-components'
 
-import { ALL_DAYS } from '../../util/monitored-trip'
+import * as userActions from '../../actions/user'
 import TripSummary from './trip-summary'
 
 // Styles.
-const StyledLabel = styled.label`
+const TripDayLabel = styled.label`
   border: 1px solid #ccc;
   border-left: none;
   box-sizing: border-box;
   display: inline-block;
   font-weight: inherit;
+  float: left;
+  height: 3em;
   max-width: 150px;
   min-width: 14.28%;
   text-align: center;
-  & > span {
+  & > span:first-of-type {
     display: block;
     width: 100%;
   }
@@ -31,73 +36,133 @@ const StyledLabel = styled.label`
 `
 
 const allDays = [
-  { name: 'monday', text: 'Mon.' },
-  { name: 'tuesday', text: 'Tue.' },
-  { name: 'wednesday', text: 'Wed.' },
-  { name: 'thursday', text: 'Thu.' },
-  { name: 'friday', text: 'Fri.' },
-  { name: 'saturday', text: 'Sat.' },
-  { name: 'sunday', text: 'Sun.' }
+  { name: 'monday', text: 'Mon.', fullText: 'Mondays' },
+  { name: 'tuesday', text: 'Tue.', fullText: 'Tuesdays' },
+  { name: 'wednesday', text: 'Wed.', fullText: 'Wednesdays' },
+  { name: 'thursday', text: 'Thu.', fullText: 'Thursdays' },
+  { name: 'friday', text: 'Fri.', fullText: 'Fridays' },
+  { name: 'saturday', text: 'Sat.', fullText: 'Saturdays' },
+  { name: 'sunday', text: 'Sun.', fullText: 'Sundays' }
 ]
 
 /**
  * This component shows summary information for a trip
  * and lets the user edit the trip name and day.
  */
-const TripBasicsPane = ({ errors, touched, values: monitoredTrip }) => {
-  const { itinerary } = monitoredTrip
-
-  if (!itinerary) {
-    return <div>No itinerary to display.</div>
-  } else {
-    // Show an error indicaton when monitoredTrip.tripName is not blank (from the form's validation schema)
-    // and that tripName is not already used.
-    let tripNameValidationState = null
-    if (touched.tripName) {
-      tripNameValidationState = errors.tripName ? 'error' : null
+class TripBasicsPane extends Component {
+  componentDidMount () {
+    // Check itinerary availability (existence) for all days.
+    const { checkItineraryExistence, values: monitoredTrip } = this.props
+    checkItineraryExistence(monitoredTrip)
+  }
+
+  componentDidUpdate (prevProps) {
+    const { isCreating, itineraryExistence, setFieldValue } = this.props
+
+    if (itineraryExistence !== prevProps.itineraryExistence) {
+      // For new trips only,
+      // update the Formik state to uncheck days for which the itinerary is not available.
+      if (isCreating && itineraryExistence) {
+        allDays.forEach(({ name }) => {
+          if (!itineraryExistence[name].valid) {
+            setFieldValue(name, false)
+          }
+        })
+      }
     }
+  }
 
-    // Show a combined error indicaton when no day is selected.
-    let monitoredDaysValidationState = null
-    ALL_DAYS.forEach(day => {
-      if (touched[day]) {
-        if (!monitoredDaysValidationState) {
-          monitoredDaysValidationState = errors[day] ? 'error' : null
-        }
+  componentWillUnmount () {
+    this.props.clearItineraryExistence()
+  }
+
+  render () {
+    const { errors, isCreating, itineraryExistence, touched, values: monitoredTrip } = this.props
+    const { itinerary } = monitoredTrip
+
+    if (!itinerary) {
+      return <div>No itinerary to display.</div>
+    } else {
+      // Show an error indicaton when monitoredTrip.tripName is not blank (from the form's validation schema)
+      // and that tripName is not already used.
+      let tripNameValidationState = null
+      if (touched.tripName) {
+        tripNameValidationState = errors.tripName ? 'error' : null
       }
-    })
-
-    return (
-      <div>
-        <ControlLabel>Selected itinerary:</ControlLabel>
-        <TripSummary monitoredTrip={monitoredTrip} />
-
-        <FormGroup validationState={tripNameValidationState}>
-          <ControlLabel>Please provide a name for this trip:</ControlLabel>
-          {/* onBlur, onChange, and value are passed automatically. */}
-          <Field as={FormControl} name='tripName' />
-          <FormControl.Feedback />
-          {errors.tripName && <HelpBlock>{errors.tripName}</HelpBlock>}
-        </FormGroup>
-
-        <FormGroup validationState={monitoredDaysValidationState}>
-          <ControlLabel>What days to you take this trip?</ControlLabel>
-          <div>
-            {allDays.map(({ name, text }, index) => (
-              <StyledLabel className={monitoredTrip[name] ? 'bg-primary' : ''} key={index}>
-                <span>{text}</span>
-                <Field
-                  name={name}
-                  type='checkbox'
-                />
-              </StyledLabel>
-            ))}
-          </div>
-          {monitoredDaysValidationState && <HelpBlock>Please select at least one day to monitor.</HelpBlock>}
-        </FormGroup>
-      </div>
-    )
+
+      // Show a combined error indicaton when no day is selected.
+      let monitoredDaysValidationState = null
+      allDays.forEach(({ name }) => {
+        if (touched[name]) {
+          if (!monitoredDaysValidationState) {
+            monitoredDaysValidationState = errors[name] ? 'error' : null
+          }
+        }
+      })
+
+      return (
+        <div>
+          <ControlLabel>Selected itinerary:</ControlLabel>
+          <TripSummary monitoredTrip={monitoredTrip} />
+
+          <FormGroup validationState={tripNameValidationState}>
+            <ControlLabel>Please provide a name for this trip:</ControlLabel>
+            {/* onBlur, onChange, and value are passed automatically. */}
+            <Field as={FormControl} name='tripName' />
+            <FormControl.Feedback />
+            {errors.tripName && <HelpBlock>{errors.tripName}</HelpBlock>}
+          </FormGroup>
+
+          <FormGroup validationState={monitoredDaysValidationState}>
+            <ControlLabel>What days do you take this trip?</ControlLabel>
+            <div>
+              {allDays.map(({ name, fullText, text }, index) => {
+                const isDayDisabled = itineraryExistence && !itineraryExistence[name].valid
+                const boxClass = isDayDisabled ? 'alert-danger' : (monitoredTrip[name] ? 'bg-primary' : '')
+                const notAvailableText = isDayDisabled ? `Trip not available on ${fullText}` : null
+
+                return (
+                  <TripDayLabel className={boxClass} key={index} title={notAvailableText}>
+                    <span>{text}</span>
+                    { // Let users save an existing trip, even though it may not be available on some days.
+                      // TODO: improve checking trip availability.
+                      isDayDisabled && isCreating
+                        ? <Glyphicon aria-label={notAvailableText} glyph='ban-circle' />
+                        : <Field name={name} type='checkbox' />
+                    }
+                  </TripDayLabel>
+                )
+              })}
+              <div style={{clear: 'both'}} />
+            </div>
+            <HelpBlock>
+              {itineraryExistence
+                ? (
+                  <>Your trip is available on the days of the week as indicated above.</>
+                ) : (
+                  <ProgressBar active label='Checking itinerary existence for each day of the week...' now={100} />
+                )
+              }
+            </HelpBlock>
+            {monitoredDaysValidationState && <HelpBlock>Please select at least one day to monitor.</HelpBlock>}
+          </FormGroup>
+        </div>
+      )
+    }
   }
 }
 
-export default TripBasicsPane
+// Connect to redux store
+const mapStateToProps = (state, ownProps) => {
+  const { itineraryExistence } = state.user
+  return {
+    itineraryExistence
+  }
+}
+
+const mapDispatchToProps = {
+  checkItineraryExistence: userActions.checkItineraryExistence,
+  clearItineraryExistence: userActions.clearItineraryExistence
+}
+
+export default connect(mapStateToProps, mapDispatchToProps)(TripBasicsPane)
diff --git a/lib/reducers/create-user-reducer.js b/lib/reducers/create-user-reducer.js
index eb5a6b430..8e7123658 100644
--- a/lib/reducers/create-user-reducer.js
+++ b/lib/reducers/create-user-reducer.js
@@ -4,6 +4,7 @@ import update from 'immutability-helper'
 function createUserReducer () {
   const initialState = {
     accessToken: null,
+    itineraryExistence: null,
     lastPhoneSmsRequest: {
       number: null,
       status: null,
@@ -41,6 +42,18 @@ function createUserReducer () {
         })
       }
 
+      case 'SET_ITINERARY_EXISTENCE': {
+        return update(state, {
+          itineraryExistence: { $set: action.payload }
+        })
+      }
+
+      case 'CLEAR_ITINERARY_EXISTENCE': {
+        return update(state, {
+          itineraryExistence: { $set: null }
+        })
+      }
+
       default:
         return state
     }