diff --git a/app/routes/support.py b/app/routes/support.py
index 23e4ddd..2db4b9e 100644
--- a/app/routes/support.py
+++ b/app/routes/support.py
@@ -182,7 +182,7 @@ def my_tickets():
 
 # ── Customer: ticket detail ───────────────────────────────────────────────────
 
-@bp.route('/my-tickets/<int:ticket_id>')
+@bp.route('/my-tickets/<int:ticket_id>', methods=['GET', 'POST'])
 @login_required
 def my_ticket_detail(ticket_id):
     if current_user.role != 'customer':
@@ -192,6 +192,36 @@ def my_ticket_detail(ticket_id):
     if ticket is None or ticket.customer_id != current_user.id:
         abort(404)
 
+    if request.method == 'POST':
+        if ticket.status == 'closed':
+            flash('This ticket is closed and cannot receive new replies.', 'warning')
+            return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))
+
+        body = request.form.get('body', '').strip()
+        if not body:
+            flash('Reply cannot be empty.', 'warning')
+            return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))
+
+        reply = SupportTicketReply(
+            ticket_id  = ticket.id,
+            user_id    = current_user.id,
+            body       = body,
+            created_at = now_eastern(),
+        )
+        db.session.add(reply)
+        # Reopen if it was answered so admin sees there's a follow-up
+        if ticket.status == 'answered':
+            ticket.status = 'open'
+        db.session.commit()
+
+        log_action(ACTION_CREATE, 'SupportTicketReply', reply.id,
+                   f'ticket #{ticket.id}',
+                   f'customer reply by {current_user.username}')
+
+        _notify_admins_customer_reply(ticket, reply)
+        flash('Your reply has been sent.', 'success')
+        return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))
+
     replies = ticket.replies.order_by(SupportTicketReply.created_at.asc()).all()
     return render_template('support/my_ticket_detail.html',
                            ticket=ticket, replies=replies)
@@ -316,3 +346,26 @@ def _notify_customer_reply(ticket, reply):
         send_email = True,
     )
     db.session.commit()
+
+
+def _notify_admins_customer_reply(ticket, reply):
+    """Notify admins when a customer adds a follow-up reply to their ticket."""
+    admins = User.query.filter_by(role='admin', active=True).all()
+    if not admins:
+        return
+
+    customer_label = ticket.customer.display_name if ticket.customer else 'Unknown'
+    link  = url_for('support.admin_ticket_detail', ticket_id=ticket.id)
+    title = f'Customer reply on ticket #{ticket.id} from {customer_label}'
+    body  = (f'Re: {ticket.subject}\n\n'
+             f'{reply.body[:400]}{"…" if len(reply.body) > 400 else ""}')
+
+    for admin in admins:
+        notify(
+            recipient  = admin,
+            title      = title,
+            body       = body,
+            link       = link,
+            send_email = True,
+        )
+    db.session.commit()
diff --git a/app/templates/support/my_ticket_detail.html b/app/templates/support/my_ticket_detail.html
index 7f2b7c0..e811146 100644
--- a/app/templates/support/my_ticket_detail.html
+++ b/app/templates/support/my_ticket_detail.html
@@ -60,7 +60,30 @@
     </div>
     {% endif %}
 
-    <div class="text-center mt-2">
+    {% if ticket.status != 'closed' %}
+    <div class="card shadow-sm mt-3">
+      <div class="card-header"><i class="bi bi-reply me-2"></i>Add a Follow-up</div>
+      <div class="card-body">
+        <form method="post">
+          <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+          <div class="mb-3">
+            <textarea name="body" class="form-control" rows="4" required
+                      placeholder="Type your follow-up message…"></textarea>
+          </div>
+          <button type="submit" class="btn btn-primary btn-sm">
+            <i class="bi bi-send me-1"></i>Send Reply
+          </button>
+        </form>
+      </div>
+    </div>
+    {% else %}
+    <div class="alert alert-secondary mt-3">
+      <i class="bi bi-lock me-2"></i>This request is closed.
+      <a href="{{ url_for('support.chat') }}">Start a new chat</a> if you need further help.
+    </div>
+    {% endif %}
+
+    <div class="text-center mt-3">
       <a href="{{ url_for('support.chat') }}" class="btn btn-outline-primary btn-sm">
         <i class="bi bi-chat-dots me-1"></i>Ask another question
       </a>