diff --git a/app/data/db.json b/app/data/db.json
index 32c8ba3..1948547 100644
--- a/app/data/db.json
+++ b/app/data/db.json
@@ -283,6 +283,7 @@
             "COVID_FLU:65+",
             "RSV:Adult"
           ],
+          "vaccinatorCount": 2,
           "slotLength": 10,
           "startDate": "2026-02-25",
           "endDate": "2026-04-30",
diff --git a/app/data/seed.js b/app/data/seed.js
index 66b6f6d..a1dd881 100644
--- a/app/data/seed.js
+++ b/app/data/seed.js
@@ -488,6 +488,7 @@ module.exports = {
           label: 'Weekday vaccination clinic',
           type: 'recurring',
           services: ['FLU:18-64', 'FLU:65+', 'COVID_FLU:18-64', 'COVID_FLU:65+', 'RSV:Adult'],
+          vaccinatorCount: 2,
           slotLength: 10,
           startDate: '2026-02-25',
           endDate:   '2026-04-30',
diff --git a/app/routes/availability.js b/app/routes/availability.js
index 9b25a77..8dff911 100644
--- a/app/routes/availability.js
+++ b/app/routes/availability.js
@@ -1,5 +1,46 @@
 // Availability routes cover creating, editing, copying, removing, and generating bookings for sessions.
 // This file owns the multi-step availability journeys and their session-backed draft state.
+function getVaccinatorCount (item) {
+  const count = parseInt(item && item.vaccinatorCount, 10)
+  return Number.isFinite(count) && count > 1 ? count : 1
+}
+
+function getHasMultipleVaccinatorsValue (item) {
+  return getVaccinatorCount(item) > 1 ? 'yes' : 'no'
+}
+
+function buildVaccinatorViewModel (item, submitted = {}) {
+  const choice = submitted.choice || getHasMultipleVaccinatorsValue(item)
+  const countValue = Object.prototype.hasOwnProperty.call(submitted, 'vaccinatorCountValue')
+    ? submitted.vaccinatorCountValue
+    : (choice === 'yes' ? String(getVaccinatorCount(item)) : '')
+
+  return {
+    hasMultipleVaccinatorsValue: choice,
+    vaccinatorCountValue: choice === 'yes' ? countValue : ''
+  }
+}
+
+function validateVaccinatorFields (body) {
+  const choice = String(body.hasMultipleVaccinators || '').trim()
+  const vaccinatorCountRaw = String(body.vaccinatorCount || '').trim()
+  const errors = []
+  let vaccinatorCount = 1
+
+  if (choice !== 'yes' && choice !== 'no') {
+    errors.push({ text: 'Select whether this session has more than one vaccinator', href: '#hasMultipleVaccinators' })
+  } else if (choice === 'yes') {
+    const parsedCount = parseInt(vaccinatorCountRaw, 10)
+    if (!/^\d+$/.test(vaccinatorCountRaw) || !Number.isFinite(parsedCount) || parsedCount < 2) {
+      errors.push({ text: 'Enter the number of vaccinators as 2 or more', href: '#vaccinatorCount' })
+    } else {
+      vaccinatorCount = parsedCount
+    }
+  }
+
+  return { choice, vaccinatorCountRaw, vaccinatorCount, errors }
+}
+
 function availability (router, shared) {
   const {
     DEFAULT_GENERATED_BOOKING_FILL_RATE,
@@ -212,7 +253,7 @@ function availability (router, shared) {
       type, label: '',
       date: '', startDate: '', endDate: '',
       dayPattern: [], startTime: '', endTime: '',
-      slotLength: '', services: [], breakTimes: [], exceptions: []
+      slotLength: '', services: [], breakTimes: [], exceptions: [], vaccinatorCount: 1
     }
     res.redirect(`/sites/${req.params.siteId}/add-availability/${type}/details`)
   })
@@ -285,7 +326,49 @@ function availability (router, shared) {
       draft.endDate = endDateCheck.value
     }
 
-    res.redirect(type === 'recurring'
+    res.redirect(`${base}/vaccinators`)
+  })
+
+  router.get('/sites/:siteId/add-availability/:type/vaccinators', (req, res) => {
+    const draft = initAddDraft(req, req.params.type)
+    const base = `/sites/${req.params.siteId}/add-availability/${req.params.type}`
+
+    res.render('sites/availability-shared-vaccinators', {
+      site: req.site,
+      draft,
+      type: req.params.type,
+      errors: [],
+      hasMultipleVaccinatorsError: null,
+      vaccinatorCountError: null,
+      ...buildVaccinatorViewModel(draft),
+      formAction: `${base}/vaccinators`,
+      backHref: `${base}/details`,
+      cancelHref: `/sites/${req.params.siteId}/availability`
+    })
+  })
+
+  router.post('/sites/:siteId/add-availability/:type/vaccinators', (req, res) => {
+    const draft = initAddDraft(req, req.params.type)
+    const base = `/sites/${req.params.siteId}/add-availability/${req.params.type}`
+    const vaccinatorCheck = validateVaccinatorFields(req.body)
+
+    if (vaccinatorCheck.errors.length) {
+      return res.render('sites/availability-shared-vaccinators', {
+        site: req.site,
+        draft,
+        type: req.params.type,
+        errors: vaccinatorCheck.errors,
+        hasMultipleVaccinatorsError: vaccinatorCheck.errors.find(e => e.href === '#hasMultipleVaccinators') ? { text: vaccinatorCheck.errors.find(e => e.href === '#hasMultipleVaccinators').text } : null,
+        vaccinatorCountError: vaccinatorCheck.errors.find(e => e.href === '#vaccinatorCount') ? { text: vaccinatorCheck.errors.find(e => e.href === '#vaccinatorCount').text } : null,
+        ...buildVaccinatorViewModel(draft, { choice: vaccinatorCheck.choice, vaccinatorCountValue: vaccinatorCheck.vaccinatorCountRaw }),
+        formAction: `${base}/vaccinators`,
+        backHref: `${base}/details`,
+        cancelHref: `/sites/${req.params.siteId}/availability`
+      })
+    }
+
+    draft.vaccinatorCount = vaccinatorCheck.vaccinatorCount
+    res.redirect(req.params.type === 'recurring'
       ? `/sites/${req.params.siteId}/add-availability/recurring/day-pattern`
       : `/sites/${req.params.siteId}/add-availability/single/times`)
   })
@@ -299,7 +382,7 @@ function availability (router, shared) {
       errors: [],
       dayPatternError: null,
       formAction: `${base}/day-pattern`,
-      backHref: `${base}/details`,
+      backHref: `${base}/vaccinators`,
       cancelHref: `/sites/${req.params.siteId}/availability`
     })
   })
@@ -317,7 +400,7 @@ function availability (router, shared) {
         errors,
         dayPatternError: { text: errors[0].text },
         formAction: `${base}/day-pattern`,
-        backHref: `${base}/details`,
+        backHref: `${base}/vaccinators`,
         cancelHref: `/sites/${req.params.siteId}/availability`
       })
     }
@@ -483,7 +566,7 @@ function availability (router, shared) {
     const base = `/sites/${req.params.siteId}/add-availability/${req.params.type}`
     const backHref = req.params.type === 'recurring'
       ? `/sites/${req.params.siteId}/add-availability/recurring/day-pattern`
-      : `${base}/details`
+      : `${base}/vaccinators`
 
     res.render('sites/availability-shared-times', {
       site: req.site,
@@ -511,7 +594,7 @@ function availability (router, shared) {
         timeBlocksError: errorMessage,
         timeBlocksHint: 'Add time when bookings can be made. Enter times like 9am, 9:00 or 13:00. We will automatically add breaks between periods. This pattern will repeat on all available days.',
         formAction: `${base}/times`,
-        backHref: req.params.type === 'recurring' ? `/sites/${req.params.siteId}/add-availability/recurring/day-pattern` : `${base}/details`,
+        backHref: req.params.type === 'recurring' ? `/sites/${req.params.siteId}/add-availability/recurring/day-pattern` : `${base}/vaccinators`,
         cancelHref: `/sites/${req.params.siteId}/availability`
       })
     }
@@ -627,6 +710,7 @@ function availability (router, shared) {
       backHref: req.params.type === 'recurring' ? `${base}/exceptions` : `${base}/services`,
       cancelHref: `/sites/${req.params.siteId}/availability`,
       detailsHref: `${base}/details`,
+      vaccinatorsHref: `${base}/vaccinators`,
       dayPatternHref: req.params.type === 'recurring' ? `/sites/${req.params.siteId}/add-availability/recurring/day-pattern` : null,
       exceptionsHref: req.params.type === 'recurring' ? `/sites/${req.params.siteId}/add-availability/recurring/exceptions` : null,
       capacityHref: `${base}/times`,
@@ -646,6 +730,7 @@ function availability (router, shared) {
       label: draft.label || 'New session',
       type: draft.type,
       services: draft.services,
+      vaccinatorCount: getVaccinatorCount(draft),
       slotLength: parseInt(draft.slotLength, 10) || 15,
       startTime,
       endTime,
@@ -774,6 +859,51 @@ function availability (router, shared) {
       working.endDate = endDateCheck.value
     }
     clearAvailabilityEditBookingDecision(req)
+    res.redirect(`${base}/vaccinators`)
+  })
+
+  router.get('/sites/:siteId/availability/:availId/edit/vaccinators', (req, res) => {
+    const working = req.session.data.editAvail
+    if (!working) return res.redirect(`/sites/${req.params.siteId}/availability/${req.params.availId}/edit`)
+    const base = `/sites/${req.params.siteId}/availability/${req.params.availId}/edit`
+
+    res.render('sites/availability-shared-vaccinators', {
+      site: req.site,
+      draft: working,
+      type: working.type,
+      errors: [],
+      hasMultipleVaccinatorsError: null,
+      vaccinatorCountError: null,
+      ...buildVaccinatorViewModel(working),
+      formAction: `${base}/vaccinators`,
+      backHref: `${base}/details`,
+      cancelHref: `/sites/${req.params.siteId}/availability`
+    })
+  })
+
+  router.post('/sites/:siteId/availability/:availId/edit/vaccinators', (req, res) => {
+    const working = req.session.data.editAvail
+    if (!working) return res.redirect(`/sites/${req.params.siteId}/availability/${req.params.availId}/edit`)
+    const base = `/sites/${req.params.siteId}/availability/${req.params.availId}/edit`
+    const vaccinatorCheck = validateVaccinatorFields(req.body)
+
+    if (vaccinatorCheck.errors.length) {
+      return res.render('sites/availability-shared-vaccinators', {
+        site: req.site,
+        draft: working,
+        type: working.type,
+        errors: vaccinatorCheck.errors,
+        hasMultipleVaccinatorsError: vaccinatorCheck.errors.find(e => e.href === '#hasMultipleVaccinators') ? { text: vaccinatorCheck.errors.find(e => e.href === '#hasMultipleVaccinators').text } : null,
+        vaccinatorCountError: vaccinatorCheck.errors.find(e => e.href === '#vaccinatorCount') ? { text: vaccinatorCheck.errors.find(e => e.href === '#vaccinatorCount').text } : null,
+        ...buildVaccinatorViewModel(working, { choice: vaccinatorCheck.choice, vaccinatorCountValue: vaccinatorCheck.vaccinatorCountRaw }),
+        formAction: `${base}/vaccinators`,
+        backHref: `${base}/details`,
+        cancelHref: `/sites/${req.params.siteId}/availability`
+      })
+    }
+
+    working.vaccinatorCount = vaccinatorCheck.vaccinatorCount
+    clearAvailabilityEditBookingDecision(req)
     res.redirect(`${base}/check`)
   })
 
@@ -1179,6 +1309,7 @@ function availability (router, shared) {
       backHref: `/sites/${req.params.siteId}/availability`,
       cancelHref: `/sites/${req.params.siteId}/availability`,
       detailsHref: `${base}/details`,
+      vaccinatorsHref: `${base}/vaccinators`,
       dayPatternHref: working.type === 'recurring' ? `${base}/day-pattern` : null,
       exceptionsHref: working.type === 'recurring' ? `${base}/exceptions` : null,
       capacityHref: `${base}/times`,
@@ -1200,6 +1331,7 @@ function availability (router, shared) {
         label: working.label || 'New session',
         type: working.type,
         services: working.services,
+        vaccinatorCount: getVaccinatorCount(working),
         slotLength: parseInt(working.slotLength, 10) || 15,
         startTime,
         endTime,
diff --git a/app/routes/shared/availability-forms.js b/app/routes/shared/availability-forms.js
index ffcb521..ca19456 100644
--- a/app/routes/shared/availability-forms.js
+++ b/app/routes/shared/availability-forms.js
@@ -7,7 +7,7 @@ function initAddDraft (req, type) {
       type, label: '',
       date: '', startDate: '', endDate: '',
       dayPattern: [], timeBlocks: [{ start: '', end: '' }],
-      slotLength: '', services: [], exceptions: []
+      slotLength: '', services: [], exceptions: [], vaccinatorCount: 1
     }
   }
   return req.session.data.addAvailDraft
diff --git a/app/routes/shared/availability-impact.js b/app/routes/shared/availability-impact.js
index 73a85bc..1418a2e 100644
--- a/app/routes/shared/availability-impact.js
+++ b/app/routes/shared/availability-impact.js
@@ -100,8 +100,10 @@ function buildAffectedSessionData (originalAvail, draftAvail, siteBookings) {
 
 function availabilityDescription (avail) {
   if (!avail) return ''
-  if (avail.type === 'single') return `${avail.label} - single on ${avail.date}`
-  return `${avail.label} - repeating ${avail.startDate} to ${avail.endDate}`
+  const vaccinatorCount = parseInt(avail.vaccinatorCount, 10) > 1 ? parseInt(avail.vaccinatorCount, 10) : 1
+  const vaccinatorText = `${vaccinatorCount} ${vaccinatorCount === 1 ? 'vaccinator' : 'vaccinators'}`
+  if (avail.type === 'single') return `${avail.label} - single on ${avail.date} - ${vaccinatorText}`
+  return `${avail.label} - repeating ${avail.startDate} to ${avail.endDate} - ${vaccinatorText}`
 }
 
 function clearAvailabilityEditBookingDecision (req) {
diff --git a/app/views/sites/availability-shared-check.html b/app/views/sites/availability-shared-check.html
index 8003ced..ccc7d2c 100644
--- a/app/views/sites/availability-shared-check.html
+++ b/app/views/sites/availability-shared-check.html
@@ -70,6 +70,26 @@ <h2 class="app-summary-card__title">Session details</h2>
       </div>
     </div>
 
+    <div class="app-summary-card">
+      <div class="app-summary-card__title-wrapper">
+        <h2 class="app-summary-card__title">Vaccinators</h2>
+        <ul class="app-summary-card__actions">
+          <li class="app-summary-card__action">
+            <a href="{{ vaccinatorsHref }}">Change<span class="nhsuk-u-visually-hidden"> vaccinators</span></a>
+          </li>
+        </ul>
+      </div>
+      <div class="app-summary-card__content">
+        {% set vaccinatorCount = draft.vaccinatorCount if draft.vaccinatorCount else 1 %}
+        {{ summaryList({ rows: [
+          {
+            key: { text: "Vaccinators" },
+            value: { text: vaccinatorCount + " " + ("vaccinator" if vaccinatorCount === 1 else "vaccinators") }
+          }
+        ] }) }}
+      </div>
+    </div>
+
     {# ══════════════════════════════════════════════════════════════════════ #}
     {# Card 2 — Day pattern (recurring only)                                 #}
     {# ══════════════════════════════════════════════════════════════════════ #}
diff --git a/app/views/sites/availability-shared-vaccinators.html b/app/views/sites/availability-shared-vaccinators.html
new file mode 100644
index 0000000..185b31d
--- /dev/null
+++ b/app/views/sites/availability-shared-vaccinators.html
@@ -0,0 +1,67 @@
+{% extends 'layout.html' %}
+
+{% set pageName = "Vaccinators — " + site.name %}
+
+{% block beforeContent %}
+  {{ backLink({ href: backHref }) }}
+{% endblock %}
+
+{% block content %}
+<div class="nhsuk-grid-row">
+  <div class="nhsuk-grid-column-two-thirds">
+
+    <span class="nhsuk-caption-xl">{{ type }}</span>
+    <h1 class="nhsuk-heading-xl">Vaccinators</h1>
+
+    {% if errors.length %}
+      {{ errorSummary({
+        titleText: "There is a problem",
+        errorList: errors
+      }) }}
+    {% endif %}
+
+    <form method="post" action="{{ formAction }}">
+
+      {% set vaccinatorCountHtml %}
+        {{ input({
+          id: "vaccinatorCount",
+          name: "vaccinatorCount",
+          value: vaccinatorCountValue,
+          label: { text: "Number of vaccinators", classes: "nhsuk-label--m" },
+          hint: { text: "Enter how many vaccinators will work in this session." },
+          errorMessage: vaccinatorCountError,
+          classes: "nhsuk-input--width-4",
+          inputmode: "numeric"
+        }) }}
+      {% endset %}
+
+      {{ radios({
+        idPrefix: "hasMultipleVaccinators",
+        name: "hasMultipleVaccinators",
+        fieldset: {
+          legend: { text: "Does this session have more than one vaccinator?", classes: "nhsuk-fieldset__legend--m" }
+        },
+        hint: { text: "Choose yes if this session should represent more than one vaccinator working at the same time." },
+        errorMessage: hasMultipleVaccinatorsError,
+        items: [
+          {
+            value: "yes",
+            text: "Yes",
+            checked: hasMultipleVaccinatorsValue === "yes",
+            conditional: { html: vaccinatorCountHtml }
+          },
+          {
+            value: "no",
+            text: "No",
+            checked: hasMultipleVaccinatorsValue === "no"
+          }
+        ]
+      }) }}
+
+      {{ button({ text: "Continue" }) }}
+
+    </form>
+
+  </div>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/app/views/sites/availability.html b/app/views/sites/availability.html
index 37b01cb..5487b08 100644
--- a/app/views/sites/availability.html
+++ b/app/views/sites/availability.html
@@ -65,11 +65,15 @@ <h1 class="nhsuk-heading-xl">Availability</h1>
         </div>
         {% endset %}
 
+        {% set vaccinatorCount = avail.vaccinatorCount if avail.vaccinatorCount else 1 %}
+        {% set vaccinatorDisplay = vaccinatorCount + " " + ("vaccinator" if vaccinatorCount === 1 else "vaccinators") %}
+
         {% set rows = (rows.push([
           { text: avail.label, header: "Session" },
           { html: typeTag, header: "Type" },
           { text: dateDisplay, header: "Date" },
           { text: daysDisplay, header: "Days" },
+          { text: vaccinatorDisplay, header: "Vaccinators" },
           { text: (avail.startTime | formatTime) + " to " + (avail.endTime | formatTime), header: "Time" },
           { text: avail.slotLength + " min", header: "Appointment length" },
           { html: actionsHtml, header: "Actions" }
@@ -85,6 +89,7 @@ <h1 class="nhsuk-heading-xl">Availability</h1>
           { text: "Type" },
           { text: "Date" },
           { text: "Days" },
+          { text: "Vaccinators" },
           { text: "Time" },
           { text: "Appointment length" },
           { text: "Actions" }