diff --git a/app/lib/utils/reading.js b/app/lib/utils/reading.js
index 491b3b23..41368bfd 100644
--- a/app/lib/utils/reading.js
+++ b/app/lib/utils/reading.js
@@ -1836,6 +1836,17 @@ const getSessionReadingProgress = (
 
   const resolvedTargetSize = session.targetSize || sessionEvents.length
 
+  // Work out how large this session can actually become right now once we
+  // account for unclaimed eligible cases. This prevents showing "25 remaining"
+  // when only (for example) 20 cases are available to read.
+  const claimedEventIds = new Set(
+    Object.values(data.readingSessions || {}).flatMap((s) => s.eventIds || [])
+  )
+  const availableTopUpCount = getEligibleCandidatesForSession(data, session)
+    .filter((event) => !claimedEventIds.has(event.id)).length
+  const reachableSessionSize = sessionEvents.length + availableTopUpCount
+  const effectiveTargetSize = Math.min(resolvedTargetSize, reachableSessionSize)
+
   // Count deferred events so they count toward the session target
   const deferredCount = sessionEvents.filter(isDeferred).length
 
@@ -1844,12 +1855,13 @@ const getSessionReadingProgress = (
     // How many events are currently loaded vs the overall target
     populatedCount: sessionEvents.length,
     targetSize: resolvedTargetSize,
+    effectiveTargetSize,
     // Deferred events count as 'done' for session progress purposes
     deferredCount,
     // Remaining reads against the target (not just currently loaded events)
     targetRemaining: Math.max(
       0,
-      resolvedTargetSize -
+      effectiveTargetSize -
         progress.userReadCount -
         progress.userAwaitingPriorsCount -
         deferredCount
diff --git a/app/routes/reading.js b/app/routes/reading.js
index 3631637b..7208516c 100644
--- a/app/routes/reading.js
+++ b/app/routes/reading.js
@@ -21,7 +21,10 @@ const {
   topUpSession,
   getReadingMetadata,
   getComparisonInfo,
-  shouldShowComparePage
+  shouldShowComparePage,
+  filterEventsByEligibleForReading,
+  filterEventsByNeedsAnyRead,
+  filterEventsByUserCanRead
 } = require('../lib/utils/reading')
 const { getShortName } = require('../lib/utils/participants')
 const { userRequestedPriors } = require('../lib/utils/prior-mammograms')
@@ -39,10 +42,28 @@ module.exports = (router) => {
 
   // Reading index — choose layout based on setting
   router.get('/reading', (req, res) => {
+    const data = req.session.data
+    const currentUserId = data?.currentUser?.id
     const layout = req.session.data?.settings?.reading?.indexLayout || 'simple'
     const template =
       layout === 'complex' ? 'reading/index-complex' : 'reading/index-simple'
-    res.render(template)
+
+    const sessionProgressById = {}
+    Object.values(data.readingSessions || {}).forEach((session) => {
+      const progress = getSessionReadingProgress(
+        data,
+        session.id,
+        null,
+        currentUserId
+      )
+      if (progress) {
+        sessionProgressById[session.id] = progress
+      }
+    })
+
+    res.render(template, {
+      sessionProgressById
+    })
   })
 
   // Default clinics list to "mine"
@@ -319,7 +340,16 @@ module.exports = (router) => {
       )
     }
 
-    res.redirect(`/reading/session/${sessionId}`)
+    // Check if there are any readable cases left in the session
+    const firstReadable = getFirstUserReadableEvent(
+      sessionEvents,
+      data.currentUser.id
+    )
+    if (firstReadable) {
+      res.redirect(`/reading/session/${sessionId}`)
+    } else {
+      res.redirect(`/reading/session/${sessionId}/no-more-cases`)
+    }
   })
 
   // Route for skipped-review page (shown at end of batch when skipped cases remain)
@@ -338,6 +368,19 @@ module.exports = (router) => {
     })
   })
 
+  // Route for no-more-cases page (shown when no more readable cases available in session)
+  router.get('/reading/session/:sessionId/no-more-cases', (req, res) => {
+    const data = req.session.data
+    const { sessionId } = req.params
+    const session = getReadingSession(data, sessionId)
+    if (!session) {
+      return res.redirect('/reading')
+    }
+    res.render('reading/no-more-cases', {
+      sessionId
+    })
+  })
+
   // Route for viewing a session with specific view
   router.get('/reading/session/:sessionId/:view', (req, res) => {
     const data = req.session.data
@@ -379,6 +422,13 @@ module.exports = (router) => {
       data.currentUser.id
     )
 
+    const sessionProgress = getSessionReadingProgress(
+      data,
+      sessionId,
+      null,
+      data.currentUser.id
+    )
+
     // Find where the user should resume — first readable after the furthest
     // point they've reached (reads or skips), falling back to first readable
     const resumeEvent = getResumeEventForUser(
@@ -410,13 +460,23 @@ module.exports = (router) => {
       clinic = data.clinics.find((c) => c.id === session.clinicId)
     }
 
+    // Overall backlog count — used to gate the 'Start a new session' button.
+    // Checks only cases the current user can actually read (not already read by them,
+    // not fully read by others, not deferred or awaiting priors).
+    const backlogTotal = filterEventsByUserCanRead(
+      filterEventsByEligibleForReading(data.events),
+      data.currentUser.id
+    ).length
+
     res.render('reading/session', {
       session,
       events: enhancedEvents,
       readingStatus,
+      sessionProgress,
       resumeEvent,
       autoFinaliseAt,
       clinic,
+      backlogTotal,
       view: selectedView
     })
   })
@@ -592,7 +652,16 @@ module.exports = (router) => {
     } else if (session.skippedEvents.length > 0) {
       res.redirect(`/reading/session/${sessionId}/skipped-review`)
     } else {
-      res.redirect(`/reading/session/${sessionId}`)
+      // Check if there are any readable cases left in the session
+      const firstReadable = getFirstUserReadableEvent(
+        sessionEvents,
+        currentUserId
+      )
+      if (firstReadable) {
+        res.redirect(`/reading/session/${sessionId}`)
+      } else {
+        res.redirect(`/reading/session/${sessionId}/no-more-cases`)
+      }
     }
   })
 
@@ -669,7 +738,16 @@ module.exports = (router) => {
           modalBreakout(`/reading/session/${sessionId}/skipped-review`)
         )
       } else {
-        res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        // Check if there are any readable cases left in the session
+        const firstReadable = getFirstUserReadableEvent(
+          sessionEvents,
+          currentUserId
+        )
+        if (firstReadable) {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        } else {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}/no-more-cases`))
+        }
       }
     }
   )
@@ -783,7 +861,16 @@ module.exports = (router) => {
           modalBreakout(`/reading/session/${sessionId}/skipped-review`)
         )
       } else {
-        res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        // Check if there are any readable cases left in the session
+        const firstReadable = getFirstUserReadableEvent(
+          sessionEvents,
+          currentUserId
+        )
+        if (firstReadable) {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        } else {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}/no-more-cases`))
+        }
       }
     }
   )
@@ -1674,7 +1761,16 @@ module.exports = (router) => {
           modalBreakout(`/reading/session/${sessionId}/skipped-review`)
         )
       } else {
-        res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        // Check if there are any readable cases left in the session
+        const firstReadable = getFirstUserReadableEvent(
+          sessionEvents,
+          currentUserId
+        )
+        if (firstReadable) {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}`))
+        } else {
+          res.redirect(modalBreakout(`/reading/session/${sessionId}/no-more-cases`))
+        }
       }
     }
   )
diff --git a/app/views/reading/history.html b/app/views/reading/history.html
index f3ef9a81..86c1b8ad 100644
--- a/app/views/reading/history.html
+++ b/app/views/reading/history.html
@@ -53,7 +53,8 @@ <h1>{{ pageHeading }}</h1>
         <tbody class="nhsuk-table__body">
           {% for session in sessions %}
             {% set p = session.progress %}
-            {% set isComplete = p and session.userCompletedCount >= p.targetSize %}
+            {% set sessionTotal = p.effectiveTargetSize if p else null %}
+            {% set isComplete = p and session.userCompletedCount >= sessionTotal %}
             <tr>
               <td>
                 <a href="/reading/session/{{ session.id }}">
@@ -78,7 +79,7 @@ <h1>{{ pageHeading }}</h1>
               </td>
               <td>
                 {% if p %}
-                  {{ p.targetSize }} total
+                  {{ sessionTotal }} total
                   {% if not isComplete %}
                     <br>{{ session.userCompletedCount }} read
                   {% endif %}
diff --git a/app/views/reading/index-simple.html b/app/views/reading/index-simple.html
index 21e702e5..f5d5fce8 100644
--- a/app/views/reading/index-simple.html
+++ b/app/views/reading/index-simple.html
@@ -8,6 +8,7 @@
 
 {% set currentUserId = data.currentUser.id %}
 {% set defaultSessionSize = data.settings.reading.defaultSessionSize or 25 %}
+{% set sessionProgressById = sessionProgressById or {} %}
 
 {#
   Build a list of the current user's sessions, most-recent first.
@@ -24,7 +25,8 @@
     {% endif %}
   {% endfor %}
   {% if userReadCount > 0 %}
-    {% set targetSize = session.targetSize or session.eventIds | length %}
+    {% set progress = sessionProgressById[session.id] %}
+    {% set targetSize = progress.effectiveTargetSize if progress else (session.targetSize or session.eventIds | length) %}
     {% set userSessions = userSessions | push({
       id: session.id,
       createdAt: session.createdAt,
@@ -100,11 +102,17 @@
 {% set urgentBacklog = backlogEvents | filterEventsByDayRange(data.config.reading.urgentThreshold) | length %}
 {% set priorityBacklog = backlogEvents | filterEventsByDayRange(data.config.reading.priorityThreshold, data.config.reading.urgentThreshold - 1) | length %}
 
+{# Cases the current user can actually read — used to gate the start button #}
+{% set userReadableTotal = data.events
+  | filterEventsByEligibleForReading
+  | filterEventsByUserCanRead(currentUserId)
+  | length %}
+
 {% block pageContent %}
   <div class="nhsuk-grid-row">
     <div class="nhsuk-grid-column-two-thirds">
       <h1>{{ pageHeading }}</h1>
-      <p>{{ backlogTotal }} cases require reading</p>
+      <p>{{ userReadableTotal }} {{ "case" | pluralise(userReadableTotal) }} available to read</p>
 
   {% if inProgressSession %}
 
@@ -117,10 +125,20 @@ <h2>Resume image reading</h2>
       href: "/reading/session/" + inProgressSession.id + "/resume"
     }) }}
 
+  {% elif userReadableTotal == 0 %}
+
+    <h2>There are no cases to read</h2>
+    <p>All cases have been read.</p>
+
+    {{ button({
+      text: "Start now",
+      disabled: true
+    }) }}
+
   {% else %}
 
     <h2>Start image reading</h2>
-    <p>Give your opinion on the next {{ defaultSessionSize }} cases due for reading.</p>
+    <p>Give your opinion on cases due for reading (up to {{ defaultSessionSize }}).</p>
 
     {{ button({
       text: "Start now",
diff --git a/app/views/reading/no-more-cases.html b/app/views/reading/no-more-cases.html
new file mode 100644
index 00000000..41fbeacf
--- /dev/null
+++ b/app/views/reading/no-more-cases.html
@@ -0,0 +1,32 @@
+{# /app/views/reading/no-more-cases.html #}
+
+{% extends 'layout-reading.html' %}
+
+{% set isReadingWorkflow = true %}
+{% set hideStatusBar = true %}
+{% set hideBackLink = true %}
+
+{% set pageHeading = "No more cases to read" %}
+
+{% block pageContent %}
+
+<div class="nhsuk-grid-row">
+  <div class="nhsuk-grid-column-two-thirds">
+
+    <span class="nhsuk-caption-l">Image reading</span>
+    <h1 class="nhsuk-heading-l">{{ pageHeading }}</h1>
+
+    <p>All eligible cases in this session have been read.</p>
+
+    <div class="nhsuk-button-group">
+      {{ button({
+        text: "Review session outcomes",
+        href: "/reading/session/" + sessionId
+      }) }}
+      <a href="/reading" class="nhsuk-link nhsuk-button-group__item">Exit reading</a>
+    </div>
+
+  </div>
+</div>
+
+{% endblock %}
diff --git a/app/views/reading/session.html b/app/views/reading/session.html
index 5356a2bf..befc48ad 100644
--- a/app/views/reading/session.html
+++ b/app/views/reading/session.html
@@ -58,13 +58,15 @@ <h1 class="nhsuk-heading-l">
       {% set sessionCompletePanelHtml %}
         <p class="nhsuk-body-m">An opinion has been provided for {{ readingStatus.userReadCount }} {{ "case" | pluralise(readingStatus.userReadCount) }}. The first opinion will be automatically finalised at {{ autoFinaliseAt | formatTime("h:mma") }}. <a href="/reading/clinics" class="nhsuk-link nhsuk-link--reverse">Finalise opinions now</a></p>
         <div class="nhsuk-button-group nhsuk-u-margin-bottom-0">
-          {{ button({
-            text: "Start a new session",
-            href: "/reading/create-session?type=all_reads",
-            variant: "reverse",
-            classes: "nhsuk-u-margin-bottom-0"
-          }) }}
-          <a href="/dashboard" class="nhsuk-link nhsuk-link--reverse nhsuk-button-group__item">Return to reading dashboard</a>
+          {% if backlogTotal > 0 %}
+            {{ button({
+              text: "Start a new session",
+              href: "/reading/create-session?type=all_reads",
+              variant: "reverse",
+              classes: "nhsuk-u-margin-bottom-0"
+            }) }}
+          {% endif %}
+          <a href="/reading" class="nhsuk-link nhsuk-link--reverse nhsuk-button-group__item">Return to reading dashboard</a>
         </div>
       {% endset %}
 
@@ -97,7 +99,8 @@ <h1 class="nhsuk-heading-l">
     }) }}
 
     {# Number of slots not yet populated in a lazy session #}
-    {% set pendingCount = (session.targetSize - session.eventIds | length) if session.targetSize else 0 %}
+    {% set sessionTotalCount = sessionProgress.effectiveTargetSize if sessionProgress else session.targetSize %}
+    {% set pendingCount = (sessionTotalCount - (session.eventIds | length)) if sessionTotalCount else 0 %}
     {% set pendingCount = 0 if pendingCount < 0 else pendingCount %}
 
     {% if view == 'your-reads' %}
@@ -217,7 +220,7 @@ <h2>Opinion summary</h2>
         {% endif %}
 
         <h2>Reading session cases</h2>
-        {% set userSessionRemainingCount = session.targetSize - readingStatus.userReadCount - readingStatus.userAwaitingPriorsCount - deferredCount %}
+        {% set userSessionRemainingCount = sessionTotalCount - readingStatus.userReadCount - readingStatus.userAwaitingPriorsCount - deferredCount %}
         {% set userSessionRemainingCount = 0 if userSessionRemainingCount < 0 else userSessionRemainingCount %}
         {% if userSessionRemainingCount > 0 or readingStatus.userAwaitingPriorsCount > 0 or deferredCount > 0 %}
           <p class="nhsuk-body app-text-grey">Progress: {{ readingStatus.userReadCount }} read{%- if readingStatus.userAwaitingPriorsCount > 0 -%}, {{ readingStatus.userAwaitingPriorsCount }} awaiting priors{%- endif -%}{%- if deferredCount > 0 -%}, {{ deferredCount }} deferred{%- endif -%}, {{ userSessionRemainingCount }} remaining</p>