diff --git a/generic/views.py b/generic/views.py
index 6c540fbe..1917d1a0 100644
--- a/generic/views.py
+++ b/generic/views.py
@@ -354,7 +354,9 @@ class ExamViews(View, LoginRequiredMixin):
 
         # We give some users the ability to filter by authors
         class ExtraExamFilter(BasicExamFilter):
-            author = ModelMultipleChoiceFilter(queryset=User.objects.all(), null_label="No author")
+            author = ModelMultipleChoiceFilter(
+                queryset=User.objects.all(), null_label="No author"
+            )
 
         self.ExtraExamFilter = ExtraExamFilter
 
@@ -476,7 +478,6 @@ class ExamViews(View, LoginRequiredMixin):
     def exam_toggle_archived(self, request, pk):
         print("TOGGLE ARCHIVED", request.POST)
         if request.method == "POST":
-
             if not self.check_user_edit_access(request.user):
                 data = {"status": "error, insufficient permission"}
                 return JsonResponse(data, status=400)
@@ -500,7 +501,6 @@ class ExamViews(View, LoginRequiredMixin):
     @method_decorator(login_required)
     def exam_toggle_results_published(self, request, pk):
         if request.method == "POST":
-
             if not self.check_user_edit_access(request.user):
                 data = {"status": "error, insufficient permission"}
                 return JsonResponse(data, status=400)
@@ -525,7 +525,6 @@ class ExamViews(View, LoginRequiredMixin):
     @method_decorator(login_required)
     def exam_toggle_active(self, request, pk):
         if request.method == "POST":
-
             if not self.check_user_edit_access(request.user):
                 data = {"status": "error, insufficient permission"}
                 return JsonResponse(data, status=400)
@@ -576,7 +575,6 @@ class ExamViews(View, LoginRequiredMixin):
 
     @method_decorator(login_required)
     def exam_list(self, request, all=False):
-
         if not self.check_user_access(request.user):
             # raise PermissionDenied
             exam_list = self.Exam.objects.filter(author__id=request.user.id).order_by(
@@ -1041,7 +1039,6 @@ class ExamViews(View, LoginRequiredMixin):
     @method_decorator(login_required)
     def exam_json_edit(self, request, pk):
         if request.method == "POST":
-
             if request.user.groups.filter(name="cid_user_manager").exists():
                 # This may give more permissions than we actually want
                 pass
@@ -1236,7 +1233,6 @@ class ExamViews(View, LoginRequiredMixin):
 
     @method_decorator(login_required)
     def index(self, request):
-
         # self.check_user_access(request.user, exam.pk)
 
         if (
@@ -1260,7 +1256,6 @@ class ExamViews(View, LoginRequiredMixin):
             exams = self.Exam.objects.filter(author__id=request.user.id)
             filter = self.BasicExamFilter(request.GET, queryset=exams)
 
-
         return render(
             request,
             "generic/exam_index.html",
@@ -1382,7 +1377,6 @@ class ExamViews(View, LoginRequiredMixin):
     @method_decorator(csrf_exempt)
     def post_exam_answers(self, request):
         if request.method == "POST":
-
             n = 0
 
             for answer in json.loads(request.POST.get("answers")):
@@ -1444,7 +1438,6 @@ class ExamViews(View, LoginRequiredMixin):
 
                 match self.app_name:
                     case "rapids":
-
                         # Normal answers are just posted with the answer "Normal"
                         normal = False
                         if posted_answer == "Normal":
@@ -1566,7 +1559,6 @@ class ExamViews(View, LoginRequiredMixin):
         return self.exam_json_unbased(request, pk, cid, passcode)
 
     def exam_json(self, request, pk, cid=None, passcode=None):
-
         exam: ExamBase = get_object_or_404(self.Exam, pk=pk)
 
         # Check access (for logged in users when inactive)
@@ -1643,7 +1635,11 @@ class ExamViews(View, LoginRequiredMixin):
         """
         exam: ExamBase = get_object_or_404(self.Exam, pk=pk)
 
-        if exam.exam_mode and not exam.active and not self.check_user_access(request.user, pk):
+        if (
+            exam.exam_mode
+            and not exam.active
+            and not self.check_user_access(request.user, pk)
+        ):
             raise Http404("No available exam")
 
         # Check access for users
@@ -1719,7 +1715,6 @@ class ExamViews(View, LoginRequiredMixin):
         if not exam.check_cid_user(cid, passcode, request, user_id):
             raise Http404("No available exam")
 
-
         return redirect("{}:question_json_unbased".format(self.app_name), pk=sk)
         redirect()
 
@@ -1823,7 +1818,6 @@ class ExamViews(View, LoginRequiredMixin):
         }
 
         if self.normalise_score is not None:
-
             normalised_score = self.normalise_score(total_score)
             template_context["normalised_score"] = normalised_score
 
@@ -1948,7 +1942,6 @@ class ExamViews(View, LoginRequiredMixin):
         user_scores_normalised = {}
         user_answer_count = {}
         for user in user_answers_marks:
-
             if self.app_name in ("rapids", "anatomy", "sbas"):
                 user_scores[user] = sum(
                     [i for i in user_answers_marks[user] if i != "unmarked"]
@@ -2364,7 +2357,6 @@ def users_bulk_delete_supervisors(request):
 
 @user_is_cid_user_manager
 def users_bulk_edit_grade(request):
-
     if request.htmx.trigger == "bulk-edit-grade-button":
         user_grades = UserGrades.objects.all()
 
@@ -2848,7 +2840,6 @@ def create_user(request, context=None):
                 )
 
             try:
-
                 user_profile = UserProfile.objects.get(user=new_user)
                 user_profile.peninsula_trainee = True
 
diff --git a/longs/models.py b/longs/models.py
index a5c347da..1b50142f 100644
--- a/longs/models.py
+++ b/longs/models.py
@@ -885,6 +885,18 @@ class CidUserAnswer(models.Model):
     def get_absolute_url(self):
         return reverse("longs:user_answer_view", kwargs={"pk": self.pk})
 
+    def get_candidate_name(self) -> str:
+        if self.cid is not None:
+            return str(self.cid)
+        else:
+            return self.user.username
+
+    def get_candidate_masked(self) -> str:
+        if self.cid is not None:
+            return str(self.cid)
+        else:
+            return str(self.user.id)
+
 
 @reversion.register
 class AnswerMarks(models.Model):
diff --git a/longs/templates/longs/mark_answer.html b/longs/templates/longs/mark_answer.html
index f9343d19..fcd9d636 100644
--- a/longs/templates/longs/mark_answer.html
+++ b/longs/templates/longs/mark_answer.html
@@ -38,22 +38,22 @@
 
     {% if not next_unmarked_id and not unmarked %}
         <div class="alert alert-info sticky-alert" role="alert">Success! Marking question complete. <br />
-        <a href="{% url 'longs:mark_answer_override' exam_id=exam.pk question_number=question_details.current|add:'-1' cid=cid %}">Set final score</a><br/>
+        <a href="{% url 'longs:mark_answer_override' exam_id=exam.pk question_number=question_details.current|add:'-1' answer_id=answer.id %}">Set final score</a><br/>
         Return to <a href="{% url 'longs:mark_question_overview' exam.id question_details.current|add:'-1' %}">question
             overview</a>, <a href="{% url 'longs:mark_overview' pk=exam.pk %}">marking
                 overview</a><br />
-            {% if previous_cid %}
-                <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' cid=previous_cid %}">Previous
+            {% if previous_answer_id %}
+                <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' answer_id=previous_answer_id %}">Previous
                     candidate</a>
             {% endif %}
-            {% if next_cid %}
-                <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' cid=next_cid %}">Next
+            {% if next_answer_id %}
+                <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' answer_id=next_answer_id %}">Next
                     candidate</a>
             {% endif %}
         </div>
     {% endif %}
 
-    <span>Marking CID: {{answer.cid}} ({{unmarked|length}} answer(s) left to mark)</span>
+    <span>Marking Candidate: {{answer.get_candidate_masked}} ({{unmarked|length}} answer(s) left to mark)</span>
     <details closed>
         <summary title="click to view/hide the question details">Question Details</summary>
         <p class="pre-whitespace"><b>Description:</b> {{ question.description }}</p>
@@ -125,11 +125,11 @@
             {% endif %}
         </form>
     </div>
-    {% if previous_cid %}
-        <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' cid=previous_cid %}">Previous
+    {% if previous_answer_id %}
+        <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' answer_id=previous_answer_id %}">Previous
             candidate</a>
     {% endif %}
-    {% if next_cid %}
-        <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' cid=next_cid %}">Next candidate</a>
+    {% if next_answer_id %}
+        <a href="{% url 'longs:mark_answer' exam_id=exam.pk question_number=question_details.current|add:'-1' answer_id=next_answer_id %}">Next candidate</a>
     {% endif %}
 {% endblock %}
diff --git a/longs/templates/longs/mark_question_double_overview.html b/longs/templates/longs/mark_question_double_overview.html
index 7a7a8026..1782a297 100644
--- a/longs/templates/longs/mark_question_double_overview.html
+++ b/longs/templates/longs/mark_question_double_overview.html
@@ -20,7 +20,7 @@
         <ul>
             {% for answer in user_answers %}
                 <li>
-                    <a href="{% url 'longs:mark_answer' exam.id question_details.current|add:'-1' answer.cid %}"
+                    <a href="{% url 'longs:mark_answer' exam.id question_details.current|add:'-1' answer.id %}"
                         title="Click to mark"> {{answer.cid}}</a>:
                     Score {{answer.get_answer_score}} [Markers: {{answer.get_markers}}] [Scores: {{answer.get_mark_scores}}]
                     {% if answer.discrepant_answers %}
diff --git a/longs/templates/longs/mark_question_single_overview.html b/longs/templates/longs/mark_question_single_overview.html
index 58417d10..b358f518 100644
--- a/longs/templates/longs/mark_question_single_overview.html
+++ b/longs/templates/longs/mark_question_single_overview.html
@@ -19,8 +19,8 @@
     <ul>
         {% for answer in user_answers %}
         <li>
-            <a href="{% url 'longs:mark_answer' exam.id question_details.current|add:'-1' answer.cid %}"
-                title="Click to mark"> {{answer.cid}}</a>:
+            <a href="{% url 'longs:mark_answer' exam.id question_details.current|add:'-1' answer.id %}"
+                title="Click to mark"> {{answer.get_candidate_masked}}</a>:
             {% if answer.is_marked %}
             Score {{answer.get_answer_score}}
             {% else %}
diff --git a/longs/urls.py b/longs/urls.py
index 4d04402b..895aaef8 100755
--- a/longs/urls.py
+++ b/longs/urls.py
@@ -68,12 +68,12 @@ urlpatterns = [
         name="question_review",
     ),
     path(
-        "exam/<int:exam_id>/<int:question_number>/<int:cid>/mark",
+        "exam/<int:exam_id>/<int:question_number>/<int:answer_id>/mark",
         views.mark_answer,
         name="mark_answer",
     ),
     path(
-        "exam/<int:exam_id>/<int:question_number>/<int:cid>/mark_override",
+        "exam/<int:exam_id>/<int:question_number>/<int:answer_id>/mark_override",
         views.mark_answer_override,
         name="mark_answer_override",
     ),
diff --git a/longs/views.py b/longs/views.py
index 3920acfe..1e8a14a4 100755
--- a/longs/views.py
+++ b/longs/views.py
@@ -625,7 +625,7 @@ def mark_answer_override(request, exam_id, question_number, cid):
 
 @user_is_long_marker
 @reversion.create_revision()
-def mark_answer(request, exam_id, question_number, cid, override=False):
+def mark_answer(request, exam_id, question_number, answer_id, override=False):
     exam = get_object_or_404(Exam, pk=exam_id)
 
     questions = exam.exam_questions.all()
@@ -643,25 +643,29 @@ def mark_answer(request, exam_id, question_number, cid, override=False):
         raise Http404("Exam question does not exist")
 
     try:
-        answer = question.cid_user_answers.get(cid=cid, exam__id=exam_id)
+        answer = question.cid_user_answers.get(pk=answer_id)
     except ObjectDoesNotExist:
         raise Http404("User answer does not exist")
 
-    cid_list = list(
-        question.cid_user_answers.filter(exam__id=exam_id).values_list("cid", flat=True)
+    answer_list = list(
+        question.cid_user_answers.filter(exam__id=exam_id).values_list("id", flat=True)
     )
 
-    previous_cid = False
-    next_cid = False
+    answer_list.sort()
+    print(answer_list)
 
-    if len(cid_list) > 1:
-        if cid_list[0] == cid:
-            next_cid = cid_list[1]
-        elif cid_list[-1] == cid:
-            previous_cid = cid_list[-2]
+    previous_answer_id = False
+    next_answer_id = False
+
+    if len(answer_list) > 1:
+        if answer_list[0] == answer_id:
+            next_answer_id = answer_list[1]
+        elif answer_list[-1] == answer_id:
+            previous_answer_id = answer_list[-2]
         else:
-            next_cid = cid_list[cid_list.index(cid) + 1]
-            previous_cid = cid_list[cid_list.index(cid) - 1]
+            print(answer_list.index(answer_id))
+            next_answer_id = answer_list[answer_list.index(answer_id) + 1]
+            previous_answer_id = answer_list[answer_list.index(answer_id) - 1]
 
     try:
         if exam.double_mark:
@@ -670,9 +674,9 @@ def mark_answer(request, exam_id, question_number, cid, override=False):
             )
         else:
             unmarked = question.get_unmarked_user_answers(exam_pk=exam.id)
-        next_unmarked_id = unmarked[0].cid
-        if next_unmarked_id == cid:
-            next_unmarked_id = unmarked[1].cid
+        next_unmarked_id = unmarked[0].id
+        if next_unmarked_id == answer_id:
+            next_unmarked_id = unmarked[1].id
     except IndexError:
         next_unmarked_id = False
 
@@ -699,14 +703,14 @@ def mark_answer(request, exam_id, question_number, cid, override=False):
                         "longs:mark_answer",
                         exam_id=exam_id,
                         question_number=question_number,
-                        cid=next_unmarked_id,
+                        answer_id=next_unmarked_id,
                     )
                 if "save" in request.POST:
                     return redirect(
                         "longs:mark_answer",
                         exam_id=exam_id,
                         question_number=question_number,
-                        cid=cid,
+                        answer_id=answer_id,
                     )
                 # elif "previous" in request.POST:
                 #    return redirect("longs:mark_question_overview", pk=exam_id, sk=n - 1)
@@ -749,14 +753,14 @@ def mark_answer(request, exam_id, question_number, cid, override=False):
                         "longs:mark_answer",
                         exam_id=exam_id,
                         question_number=question_number,
-                        cid=next_unmarked_id,
+                        answer_id=next_unmarked_id,
                     )
                 if "save" in request.POST:
                     return redirect(
                         "longs:mark_answer",
                         exam_id=exam_id,
                         question_number=question_number,
-                        cid=cid,
+                        answer_id=answer_id,
                     )
                 # elif "previous" in request.POST:
                 #    return redirect("longs:mark_question_overview", pk=exam_id, sk=n - 1)
@@ -797,9 +801,9 @@ def mark_answer(request, exam_id, question_number, cid, override=False):
             "question_details": question_details,
             "next_unmarked_id": next_unmarked_id,
             "unmarked": unmarked,
-            "previous_cid": previous_cid,
-            "next_cid": next_cid,
-            "cid": cid,
+            "previous_answer_id": previous_answer_id,
+            "next_answer_id": next_answer_id,
+            "answer_id": answer_id,
         },
     )