diff --git a/easy_toolbox.py b/easy_toolbox.py
index f617208eb..77d196b09 100755
--- a/easy_toolbox.py
+++ b/easy_toolbox.py
@@ -3,7 +3,7 @@
 # pip requirements:
 #   python ^3.6
 #   inquirer     (only for GUI)
-# 
+#
 # system:
 #   docker
 #   docker-compose
@@ -37,7 +37,7 @@
     ("test", "Run unit tests.", "{exec} web ../oioioi/test.sh"),
     ("test-slow", "Run unit tests. (--runslow)", "{exec} web ../oioioi/test.sh --runslow"),
     ("test-abc", "Run specific test file. (edit the toolbox)",
-     "{exec} web ../oioioi/test.sh -v oioioi/problems/tests/test_task_archive.py"),
+     "{exec} web ../oioioi/test.sh -v oioioi/teachers/tests.py"),
     ("test-coverage", "Run coverage tests.",
      "{exec} 'web' ../oioioi/test.sh oioioi/problems --cov-report term --cov-report xml:coverage.xml --cov=oioioi"),
     ("cypress-apply-settings", "Apply settings for CyPress.",
diff --git a/oioioi/teachers/forms.py b/oioioi/teachers/forms.py
index 179ec764b..ea9a68e09 100644
--- a/oioioi/teachers/forms.py
+++ b/oioioi/teachers/forms.py
@@ -2,11 +2,14 @@
 from django.urls import reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
+from django.contrib import messages
+from django.core.exceptions import ValidationError
 
 from oioioi.contests.forms import SimpleContestForm
-from oioioi.teachers.models import Teacher
+from oioioi.teachers.models import ContestTeacher, Teacher
 from oioioi.base.utils.user_selection import UserSelectionField
-
+from oioioi.participants.models import Participant
+from oioioi.teachers.utils import validate_can_add_user_to_contest, add_user_to_contest_as
 
 
 class TeacherContestForm(SimpleContestForm):
@@ -83,3 +86,24 @@ def __init__(self, *args, **kwargs):
     def clean_school(self):
         data = self.cleaned_data['school']
         return ' '.join(data.splitlines())
+
+
+class AddUserToContestForm(forms.Form):
+    user = UserSelectionField()
+
+    def __init__(self, member_type, contest, *args, **kwargs):
+        self.member_type = member_type
+        self.contest = contest
+        super(AddUserToContestForm, self).__init__(*args, **kwargs)
+
+    def clean(self):
+        clean_data = super().clean()
+
+        if self.is_valid():
+            user = self.cleaned_data['user']
+            try:
+                validate_can_add_user_to_contest(user, self.contest, self.member_type)
+            except ValidationError as e:
+                self.add_error('user', e.message)
+
+        return clean_data
diff --git a/oioioi/teachers/templates/teachers/members.html b/oioioi/teachers/templates/teachers/members.html
index dfc7c0774..9d6468e4b 100644
--- a/oioioi/teachers/templates/teachers/members.html
+++ b/oioioi/teachers/templates/teachers/members.html
@@ -176,6 +176,25 @@ <h2 class="method-title" id="members-view">
                 </p>
             {% endif %}
 
+            <form action="{% url 'teachers_add_user_to_contest' contest_id=contest.id member_type=member_type %}" method="post">
+                {% csrf_token %}
+                <input type="hidden" name="next" value="{{ ctx.request.get_full_path }}">
+
+                <div class="input-group mb-3">
+                    <div class="input-group-prepend">
+                        <button class="btn btn-success" type="submit">
+                            {% if member_type == 'teacher' %}
+                                {% trans "Add a teacher" %}
+                            {% else %}
+                                {% trans "Add a pupil" %}
+                            {% endif %}
+                        </button>
+                    </div>
+                    <input type="text" name="user" id="new-user" class="form-control" placeholder="{% trans "Username" %}" data-hints-url="{% url 'teachers_get_appendable_users' contest_id=contest.id member_type=member_type %}">
+                    <script>init_user_selection("new-user", {{ num_hints }})</script>
+                </div>
+            </form>
+
             {% if member_type == 'pupil' and usergroups_active and members %}
                 <div class="text-center">
                     <form class="convert-members" action="{% url 'teacher_usergroups_add_group' %}" method="get">
diff --git a/oioioi/teachers/tests.py b/oioioi/teachers/tests.py
index 5e83cb1a6..edf1197aa 100644
--- a/oioioi/teachers/tests.py
+++ b/oioioi/teachers/tests.py
@@ -6,6 +6,9 @@
 from oioioi.contests.tests import make_empty_contest_formset
 from oioioi.contests.tests.utils import make_user_contest_admin
 from oioioi.teachers.models import Teacher
+from django.core.exceptions import ValidationError
+
+from oioioi.teachers.utils import add_user_to_contest_as
 
 
 def change_contest_type(contest):
@@ -28,7 +31,8 @@ def test_problemset_permissions(self):
         response = self.client.get(url_add, follow=True)
         self.assertEqual(response.status_code, 200)
 
-        self.assertTrue(self.client.login(username='test_user2'))  # test_user2 is not
+        self.assertTrue(
+            self.client.login(username='test_user2'))  # test_user2 is not
         response = self.client.get(url_main)
         self.assertEqual(response.status_code, 200)
         self.assertNotContains(response, 'Add problem')
@@ -181,3 +185,99 @@ def test_teacher_modify(self):
         self.assertEqual(Teacher.objects.all().count(), 2)
         mod_teacher = Teacher.objects.get(pk=1001)
         self.assertEqual(mod_teacher.school, "New School")
+
+
+class TestAddUserToContestForm(TestCase):
+    fixtures = ['test_users', 'teachers', 'test_contest']
+
+    def setUp(self):
+        self.user = User.objects.get(username='test_user')
+        self.c = Contest.objects.get(id='c')
+
+        # In order to get the required URL for tests,
+        # we have to first get it as a regular teacher.
+        self.assertTrue(self.client.login(username='test_user'))
+        add_user_to_contest_as(self.user, self.c, 'teacher')
+        self.url_add_teacher = reverse(
+            'teachers_add_user_to_contest',
+            kwargs={'contest_id':self.c.id, 'member_type':'teacher'})
+        self.url_add_pupil = reverse(
+            'teachers_add_user_to_contest',
+            kwargs={'contest_id':self.c.id, 'member_type':'pupil'})
+        self.assertTrue(
+            self.c.contestteacher_set
+            .filter(teacher__user=self.user)
+            .first().delete())
+        self.client.logout()
+
+    def test_add_user_to_contest_as_pupil(self):
+        self.assertFalse(self.c.participant_set.filter(user=self.user))
+        add_user_to_contest_as(self.user, self.c, 'pupil')
+        self.assertTrue(self.c.participant_set.filter(user=self.user))
+
+        with self.assertRaisesRegex(ValidationError, 'User is already added'):
+            add_user_to_contest_as(self.user, self.c, 'pupil')
+        with self.assertRaisesRegex(ValidationError, 'User is already added'):
+            add_user_to_contest_as(self.user, self.c, 'teacher')
+
+    def test_add_user_to_contest_as_teacher(self):
+        self.assertFalse(
+            self.c.contestteacher_set.filter(teacher__user=self.user))
+        add_user_to_contest_as(self.user, self.c, 'teacher')
+        self.assertTrue(
+            self.c.contestteacher_set.filter(teacher__user=self.user))
+
+        with self.assertRaisesRegex(ValidationError, 'User is already added'):
+            add_user_to_contest_as(self.user, self.c, 'pupil')
+        with self.assertRaisesRegex(ValidationError, 'User is already added'):
+            add_user_to_contest_as(self.user, self.c, 'teacher')
+
+    def test_add_non_teacher_as_teacher(self):
+        not_teacher = User.objects.filter(is_superuser=False,
+                                          teacher__isnull=True,
+                                          is_active=True).first()
+
+        with self.assertRaisesRegex(ValidationError, 'User is not a teacher'):
+            add_user_to_contest_as(not_teacher, self.c, 'teacher')
+        self.assertFalse(
+            self.c.contestteacher_set.filter(teacher__user=self.user))
+        add_user_to_contest_as(not_teacher, self.c, 'pupil')
+        with self.assertRaisesRegex(ValidationError, 'User is already added'):
+            add_user_to_contest_as(not_teacher, self.c, 'teacher')
+
+    def test_http_logged_out(self):
+        post_data = { 'user': 'test_user' }
+
+        for url in [self.url_add_pupil, self.url_add_teacher]:
+            response = self.client.post(url, post_data, Follow=False)
+            self.assertEqual(response.status_code, 302)
+            self.assertIn('/login/?next=', response['Location'])
+            self.assertTrue(response['Location'].endswith(url))
+
+            # Check if it has not added any new users.
+            self.assertFalse(
+                self.c.contestteacher_set.filter(teacher__user=self.user))
+            self.assertFalse(
+                self.c.participant_set.filter(user=self.user))
+
+    def test_http_logged_in(self):
+        self.assertTrue(self.client.login(username='test_user'))
+
+        # Make sure 'test_user' is not a contest teacher.
+        self.assertFalse(
+            self.c.contestteacher_set.filter(teacher__user=self.user))
+        self.assertFalse(
+            self.c.participant_set.filter(user=self.user))
+
+        def try_add():
+            post_data = { 'user': 'test_user2' }  # Some other user
+            for url in [self.url_add_pupil, self.url_add_teacher]:
+                response = self.client.post(url, post_data, Follow=False)
+                self.assertEqual(response.status_code, 403)
+
+        try_add()
+
+        # Retry as a contest pupil.
+        add_user_to_contest_as(self.user, self.c, 'pupil')
+        self.assertTrue(self.c.participant_set.filter(user=self.user))
+        try_add()
diff --git a/oioioi/teachers/urls.py b/oioioi/teachers/urls.py
index cfcf3fb96..1fa49b648 100644
--- a/oioioi/teachers/urls.py
+++ b/oioioi/teachers/urls.py
@@ -25,6 +25,15 @@
         name='teachers_regenerate_key',
     ),
     re_path(r'^delete/$', views.delete_members_view, name='teachers_delete_members'),
+
+    re_path(
+        r'^registration/add_user/$',
+        views.add_user_to_contest,
+        name='teachers_add_user_to_contest'),
+    re_path(
+        r'^registration/get_appendable_users/$',
+        views.get_appendable_users_view,
+        name='teachers_get_appendable_users'),
 ]
 
 contest_patterns = [
diff --git a/oioioi/teachers/utils.py b/oioioi/teachers/utils.py
new file mode 100644
index 000000000..a39ebc08e
--- /dev/null
+++ b/oioioi/teachers/utils.py
@@ -0,0 +1,65 @@
+from oioioi.participants.models import Participant
+from oioioi.teachers.models import ContestTeacher, Teacher
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+
+def get_user_teacher_obj(user):
+    try:
+        return user.teacher
+    except Teacher.DoesNotExist:
+        return None
+
+
+def is_user_already_in_contest(user, contest):
+    teacher = get_user_teacher_obj(user)
+
+    if user.participant_set.filter(contest=contest) or \
+       (teacher and
+       teacher.contestteacher_set.filter(contest=contest)):
+        return True
+
+    return False
+
+
+def validate_can_add_user_to_contest(user, contest, member_type):
+    exists = False
+
+    if not is_user_already_in_contest(user, contest):
+        if member_type == 'pupil':
+            exists = len(Participant.objects.filter(
+                contest=contest, user=user
+            )) > 0
+        elif member_type == 'teacher':
+            if teacher := get_user_teacher_obj(user):
+                exists = len(ContestTeacher.objects.filter(
+                    contest=contest, teacher=teacher
+                )) > 0
+            else:
+                raise ValidationError(
+                    _("User is not a teacher: \'%(user)s\'")
+                    % {"user": user })
+        else:
+            raise ValueError("Invalid member type")
+    else:
+        exists = True
+
+    if exists:
+        raise ValidationError(
+            _("User is already added: \'%(user)s\'")
+            % { "user": user })
+
+
+def add_user_to_contest_as(user, contest, member_type):
+    validate_can_add_user_to_contest(user, contest, member_type)
+    created = False
+
+    if member_type == 'pupil':
+        Participant.objects.get_or_create(
+            contest=contest, user=user
+        )
+    elif member_type == 'teacher':
+        teacher = get_user_teacher_obj(user)
+        ContestTeacher.objects.get_or_create(
+            contest=contest, teacher=teacher
+        )
diff --git a/oioioi/teachers/views.py b/oioioi/teachers/views.py
index cc45a9c62..b31cb4170 100644
--- a/oioioi/teachers/views.py
+++ b/oioioi/teachers/views.py
@@ -27,8 +27,11 @@
 from oioioi.contests.utils import contest_exists, is_contest_admin
 from oioioi.participants.models import Participant
 from oioioi.teachers.controllers import TeacherContestController
-from oioioi.teachers.forms import AddTeacherForm
+from oioioi.teachers.forms import AddTeacherForm, AddUserToContestForm
 from oioioi.teachers.models import ContestTeacher, RegistrationConfig, Teacher
+from oioioi.teachers.utils import \
+    is_user_already_in_contest, get_user_teacher_obj, add_user_to_contest_as
+from django.core.exceptions import ValidationError
 
 if 'oioioi.usergroups' in settings.INSTALLED_APPS:
     import oioioi.usergroups.utils as usergroups
@@ -398,3 +401,42 @@ def contest_dashboard_redirect(request):
                     kwargs={'contest_id': request.contest.id},
                 )
             )
+
+
+@enforce_condition(is_teachers_contest & is_contest_admin)
+def get_appendable_users_view(request, member_type):
+    users = User.objects.filter(is_superuser=False, is_active=True)
+    if member_type == 'teacher':
+        users = users.filter(teacher__isnull=False)
+
+    return get_user_hints_view(request, 'substr', users)
+
+
+@require_POST
+@enforce_condition(contest_exists & is_teachers_contest & is_contest_admin)
+def add_user_to_contest(request, member_type):
+    form = AddUserToContestForm(member_type, request.contest, request.POST)
+    try:
+        if form.is_valid():
+            user = form.cleaned_data['user']
+
+            try:
+                add_user_to_contest_as(
+                    user,
+                    request.contest,
+                    member_type
+                )
+                messages.success(
+                    request,
+                    _('User \'%(user)s\' successfully added as a \'%(member_type)s\'.')
+                    % {'user': user, 'member_type': member_type})
+
+            except ValidationError as e:
+                messages.error(request, e.message)
+        else:
+            for err in form.errors.as_data()['user']:
+                messages.error(request, err.message)
+    except ValidationError as e:
+        messages.error(e.message)
+
+    return redirect_to_members(request, member_type)