diff --git a/snikket_web/admin.py b/snikket_web/admin.py
index b21a851..8a0e829 100644
--- a/snikket_web/admin.py
+++ b/snikket_web/admin.py
@@ -272,6 +272,12 @@ async def create_circle() -> typing.Union[str, quart.Response]:
 class EditCircleForm(flask_wtf.FlaskForm):  # type:ignore
     name = wtforms.StringField(
         _l("Name"),
+        validators=[wtforms.validators.InputRequired()],
+    )
+
+    user_to_add = wtforms.SelectField(
+        _l("Select user"),
+        validate_choice=False,
     )
 
     action_save = wtforms.SubmitField(
@@ -284,6 +290,10 @@ class EditCircleForm(flask_wtf.FlaskForm):  # type:ignore
 
     action_remove_user = wtforms.StringField()
 
+    action_add_user = wtforms.SubmitField(
+        _l("Add user")
+    )
+
 
 @bp.route("/circle/<id_>", methods=["GET", "POST"])
 @client.require_admin_session()
@@ -307,22 +317,51 @@ async def edit_circle(id_: str) -> typing.Union[str, quart.Response]:
             for localpart in sorted(circle.members)
         ))
 
+        users = await client.list_users()
+
     form = EditCircleForm()
+    form.user_to_add.choices = sorted(
+        (
+            (u.localpart, u.localpart)
+            for u in users
+            if u.localpart not in circle.members
+        ),
+        key=lambda x: x[1]
+    )
+    valid_users = [x[0] for x in form.user_to_add.choices]
+
     invite_form = InvitePost()
     await invite_form.init_choices()
     invite_form.circles.data = [id_]
 
     if request.method != "POST":
         form.name.data = circle.name
+
     if form.validate_on_submit():
         if form.action_save.data:
-            # TODO: post update
-            pass
+            await client.update_group(
+                id_,
+                new_name=form.name.data,
+            )
         elif form.action_delete.data:
             await client.delete_group(id_)
             return redirect(url_for(".circles"))
+        elif form.action_add_user.data:
+            if form.user_to_add.data in valid_users:
+                print("is valid")
+                await client.add_group_member(
+                    id_,
+                    form.user_to_add.data,
+                )
+        elif form.action_remove_user.data:
+            await client.remove_group_member(
+                id_,
+                form.action_remove_user.data,
+            )
 
         return redirect(url_for(".edit_circle", id_=id_))
+    else:
+        print(form.errors)
 
     return await render_template(
         "admin_edit_circle.html",
diff --git a/snikket_web/prosodyclient.py b/snikket_web/prosodyclient.py
index bd27f0d..9aa869e 100644
--- a/snikket_web/prosodyclient.py
+++ b/snikket_web/prosodyclient.py
@@ -108,7 +108,7 @@ class AdminGroupInfo:
         return cls(
             id_=data["id"],
             name=data["name"],
-            members=data["members"],
+            members=data.get("members", []),
         )
 
 
@@ -924,7 +924,47 @@ class ProsodyClient:
             new_name: typing.Optional[str] = None,
             session: aiohttp.ClientSession,
             ) -> AdminGroupInfo:
-        pass
+        payload = {}
+        if new_name is not None:
+            payload["name"] = new_name
+
+        async with session.put(
+                self._admin_v1_endpoint(
+                    "/groups/{}".format(id_)
+                ),
+                json=payload,
+                ) as resp:
+            self._raise_error_from_response(resp)
+
+    @autosession
+    async def add_group_member(
+            self,
+            id_: str,
+            localpart: str,
+            *,
+            session: aiohttp.ClientSession,
+            ) -> None:
+        async with session.put(
+                self._admin_v1_endpoint(
+                    "/groups/{}/members/{}".format(id_, localpart)
+                ),
+                ) as resp:
+            self._raise_error_from_response(resp)
+
+    @autosession
+    async def remove_group_member(
+            self,
+            id_: str,
+            localpart: str,
+            *,
+            session: aiohttp.ClientSession,
+            ) -> None:
+        async with session.delete(
+                self._admin_v1_endpoint(
+                    "/groups/{}/members/{}".format(id_, localpart)
+                ),
+                ) as resp:
+            self._raise_error_from_response(resp)
 
     @autosession
     async def delete_group(
diff --git a/snikket_web/templates/admin_edit_circle.html b/snikket_web/templates/admin_edit_circle.html
index cf05258..b884fd0 100644
--- a/snikket_web/templates/admin_edit_circle.html
+++ b/snikket_web/templates/admin_edit_circle.html
@@ -2,9 +2,10 @@
 {% from "library.j2" import form_button, standard_button, value_or_hint, custom_form_button %}
 {% block content %}
 <h1>{% trans circle_name=(target_circle | circle_name) %}Edit circle {{ circle_name }}{% endtrans %}</h1>
-<div class="form layout-expanded"><form method="POST">
+<form method="POST">
+{{- form.csrf_token -}}
+<div class="form layout-expanded">
 	<h2 class="form-title">{% trans %}Circle information{% endtrans %}</h2>
-	{{ form.csrf_token }}
 	<div class="f-ebox">
 		{{ form.name.label }}
 		{{ form.name }}
@@ -22,6 +23,7 @@
 	</div>
 </div>
 <h2>{% trans %}Circle members{% endtrans %}</h2>
+{%- if circle_members -%}
 <div class="el-2 elevated"><table>
 	<thead>
 		<th>Login name</th>
@@ -42,7 +44,27 @@
 {%- endfor -%}
 	</tbody>
 </table></div>
-</form>
+{%- else -%}
+<p>{% trans %}This circle currently has no members.{% endtrans %}</p>
+{%- endif -%}
 <h3>{% trans %}Invite more members{% endtrans %}</h3>
+{%- if form.user_to_add.choices -%}
+<div class="form layout-expanded">
+	<h4 class="form-title">{% trans %}Add existing user{% endtrans %}</h4>
+	<div class="f-ebox">
+		{{- form.user_to_add.label -}}
+		<div class="select-wrap">{{ form.user_to_add }}</div>
+	</div>
+	<div class="f-bbox">
+		{%- call form_button("add", form.action_add_user, class="primary") %}{% endcall -%}
+	</div>
+</div>
+{%- else -%}
+<div class="box hint el-2">
+	<header>{% trans %}No users left{% endtrans %}</header>
+	<p>{% trans %}All users on this instance are already in this circle.{% endtrans %}</p>
+</div>
+{%- endif -%}
+</form>
 {%- include "admin_create_invite_form.html" -%}
 {% endblock %}
diff --git a/snikket_web/templates/admin_invites.html b/snikket_web/templates/admin_invites.html
index 8edbcef..e0b100e 100644
--- a/snikket_web/templates/admin_invites.html
+++ b/snikket_web/templates/admin_invites.html
@@ -34,7 +34,12 @@
 				{#- -#}
 				<ul class="inline">
 				{%- for group_id in invite.group_ids -%}
+					{%- set circle_info = circle_map[group_id] -%}
+					{%- if circle_info -%}
 					<li>{{ circle_map[group_id] | circle_name }}</li>
+					{%- else -%}
+					<li><em>{% trans %}deleted{% endtrans %}</em></li>
+					{%- endif -%}
 				{%- endfor -%}
 				</ul>
 				{#- -#}
diff --git a/snikket_web/translations/de/LC_MESSAGES/messages.po b/snikket_web/translations/de/LC_MESSAGES/messages.po
index 79c7b39..c26699a 100644
--- a/snikket_web/translations/de/LC_MESSAGES/messages.po
+++ b/snikket_web/translations/de/LC_MESSAGES/messages.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: SnikketWeb 0.1.0\n"
 "Report-Msgid-Bugs-To: jonas@zombofant.net\n"
-"POT-Creation-Date: 2021-01-21 17:00+0100\n"
+"POT-Creation-Date: 2021-01-21 17:39+0100\n"
 "PO-Revision-Date: 2020-03-07 16:32+0100\n"
 "Last-Translator: Jonas Schäfer <jonas@zombofant.net>\n"
 "Language: de\n"
@@ -74,14 +74,22 @@ msgstr "Name"
 msgid "Create circle"
 msgstr "Gemeinschaft gründen"
 
-#: snikket_web/admin.py:278 snikket_web/user.py:68
+#: snikket_web/admin.py:279
+msgid "Select user"
+msgstr "Benutzer auswählen"
+
+#: snikket_web/admin.py:284 snikket_web/user.py:68
 msgid "Apply"
 msgstr "Übernehmen"
 
-#: snikket_web/admin.py:282
+#: snikket_web/admin.py:288
 msgid "Delete circle permanently"
 msgstr "Gemeinschaft endgültig löschen"
 
+#: snikket_web/admin.py:294
+msgid "Add user"
+msgstr "Benutzer hinzufügen"
+
 #: snikket_web/infra.py:40
 msgid "Main"
 msgstr "Kern"
@@ -334,7 +342,7 @@ msgid "Danger"
 msgstr "Gefahr"
 
 #: snikket_web/templates/admin_delete_user.html:23
-#: snikket_web/templates/admin_edit_circle.html:14
+#: snikket_web/templates/admin_edit_circle.html:15
 #: snikket_web/templates/admin_edit_invite.html:45
 #: snikket_web/templates/user_logout.html:13
 #: snikket_web/templates/user_passwd.html:40
@@ -347,33 +355,49 @@ msgstr "Zurück"
 msgid "Edit circle %(circle_name)s"
 msgstr "Gemeinschaft %(circle_name)s bearbeiten"
 
-#: snikket_web/templates/admin_edit_circle.html:6
+#: snikket_web/templates/admin_edit_circle.html:8
 msgid "Circle information"
 msgstr "Gemeinschaftsinformationen"
 
-#: snikket_web/templates/admin_edit_circle.html:18
+#: snikket_web/templates/admin_edit_circle.html:19
 msgid "Delete circle"
 msgstr "Gemeinschaft löschen"
 
-#: snikket_web/templates/admin_edit_circle.html:19
+#: snikket_web/templates/admin_edit_circle.html:20
 msgid "Deleting a circle does not delete any users in the circle."
 msgstr ""
 "Wenn eine Gemeinschaft gelöscht wird, werden die Benutzer die zu dieser "
 "Gemeinschaft gehören nicht gelöscht."
 
-#: snikket_web/templates/admin_edit_circle.html:24
+#: snikket_web/templates/admin_edit_circle.html:25
 msgid "Circle members"
 msgstr "Mitglieder der Gemeinschaft"
 
-#: snikket_web/templates/admin_edit_circle.html:38
+#: snikket_web/templates/admin_edit_circle.html:40
 #, python-format
 msgid "Remove user %(username)s from circle"
 msgstr "Benutzer %(username)s aus der Gemeinschaft entfernen"
 
-#: snikket_web/templates/admin_edit_circle.html:46
+#: snikket_web/templates/admin_edit_circle.html:48
+msgid "This circle currently has no members."
+msgstr "Diese Gemeinschaft hat derzeit keine Mitglieder."
+
+#: snikket_web/templates/admin_edit_circle.html:50
 msgid "Invite more members"
 msgstr "Mehr Mitglieder einladen"
 
+#: snikket_web/templates/admin_edit_circle.html:53
+msgid "Add existing user"
+msgstr "Bestehenden Benuzter hinzufügen"
+
+#: snikket_web/templates/admin_edit_circle.html:64
+msgid "No users left"
+msgstr "Keine Benutzer übrig"
+
+#: snikket_web/templates/admin_edit_circle.html:65
+msgid "All users on this instance are already in this circle."
+msgstr "Alle Benutzer dieser Instanz sind bereits in dieser Gemeinschaft."
+
 #: snikket_web/templates/admin_edit_invite.html:8
 msgid "View invitation"
 msgstr "Einladung anzeigen"
@@ -505,19 +529,23 @@ msgstr "Ja"
 msgid "No"
 msgstr "Nein"
 
-#: snikket_web/templates/admin_invites.html:44
+#: snikket_web/templates/admin_invites.html:41
+msgid "deleted"
+msgstr "gelöscht"
+
+#: snikket_web/templates/admin_invites.html:49
 msgid "Show invite details"
 msgstr "Einladungsdetails anzeigen"
 
-#: snikket_web/templates/admin_invites.html:47
+#: snikket_web/templates/admin_invites.html:52
 msgid "Copy invite link to clipboard"
 msgstr "Einladungslink kopieren"
 
-#: snikket_web/templates/admin_invites.html:50
+#: snikket_web/templates/admin_invites.html:55
 msgid "Delete invitation"
 msgstr "Einladung löschen"
 
-#: snikket_web/templates/admin_invites.html:58
+#: snikket_web/templates/admin_invites.html:63
 msgid "Currently, there are no pending invitations."
 msgstr "Derzeit gibt es keine ausstehenden Einladungen."
 
diff --git a/snikket_web/translations/en/LC_MESSAGES/messages.po b/snikket_web/translations/en/LC_MESSAGES/messages.po
index 6e4ef1f..100bef1 100644
--- a/snikket_web/translations/en/LC_MESSAGES/messages.po
+++ b/snikket_web/translations/en/LC_MESSAGES/messages.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PROJECT VERSION\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2021-01-21 17:00+0100\n"
+"POT-Creation-Date: 2021-01-21 17:39+0100\n"
 "PO-Revision-Date: 2020-03-07 16:50+0100\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language: en\n"
@@ -74,14 +74,22 @@ msgstr ""
 msgid "Create circle"
 msgstr ""
 
-#: snikket_web/admin.py:278 snikket_web/user.py:68
+#: snikket_web/admin.py:279
+msgid "Select user"
+msgstr ""
+
+#: snikket_web/admin.py:284 snikket_web/user.py:68
 msgid "Apply"
 msgstr ""
 
-#: snikket_web/admin.py:282
+#: snikket_web/admin.py:288
 msgid "Delete circle permanently"
 msgstr ""
 
+#: snikket_web/admin.py:294
+msgid "Add user"
+msgstr ""
+
 #: snikket_web/infra.py:40
 msgid "Main"
 msgstr ""
@@ -320,7 +328,7 @@ msgid "Danger"
 msgstr ""
 
 #: snikket_web/templates/admin_delete_user.html:23
-#: snikket_web/templates/admin_edit_circle.html:14
+#: snikket_web/templates/admin_edit_circle.html:15
 #: snikket_web/templates/admin_edit_invite.html:45
 #: snikket_web/templates/user_logout.html:13
 #: snikket_web/templates/user_passwd.html:40
@@ -333,31 +341,47 @@ msgstr ""
 msgid "Edit circle %(circle_name)s"
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:6
+#: snikket_web/templates/admin_edit_circle.html:8
 msgid "Circle information"
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:18
+#: snikket_web/templates/admin_edit_circle.html:19
 msgid "Delete circle"
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:19
+#: snikket_web/templates/admin_edit_circle.html:20
 msgid "Deleting a circle does not delete any users in the circle."
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:24
+#: snikket_web/templates/admin_edit_circle.html:25
 msgid "Circle members"
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:38
+#: snikket_web/templates/admin_edit_circle.html:40
 #, python-format
 msgid "Remove user %(username)s from circle"
 msgstr ""
 
-#: snikket_web/templates/admin_edit_circle.html:46
+#: snikket_web/templates/admin_edit_circle.html:48
+msgid "This circle currently has no members."
+msgstr ""
+
+#: snikket_web/templates/admin_edit_circle.html:50
 msgid "Invite more members"
 msgstr ""
 
+#: snikket_web/templates/admin_edit_circle.html:53
+msgid "Add existing user"
+msgstr ""
+
+#: snikket_web/templates/admin_edit_circle.html:64
+msgid "No users left"
+msgstr ""
+
+#: snikket_web/templates/admin_edit_circle.html:65
+msgid "All users on this instance are already in this circle."
+msgstr ""
+
 #: snikket_web/templates/admin_edit_invite.html:8
 msgid "View invitation"
 msgstr ""
@@ -479,19 +503,23 @@ msgstr ""
 msgid "No"
 msgstr ""
 
-#: snikket_web/templates/admin_invites.html:44
+#: snikket_web/templates/admin_invites.html:41
+msgid "deleted"
+msgstr ""
+
+#: snikket_web/templates/admin_invites.html:49
 msgid "Show invite details"
 msgstr ""
 
-#: snikket_web/templates/admin_invites.html:47
+#: snikket_web/templates/admin_invites.html:52
 msgid "Copy invite link to clipboard"
 msgstr ""
 
-#: snikket_web/templates/admin_invites.html:50
+#: snikket_web/templates/admin_invites.html:55
 msgid "Delete invitation"
 msgstr ""
 
-#: snikket_web/templates/admin_invites.html:58
+#: snikket_web/templates/admin_invites.html:63
 msgid "Currently, there are no pending invitations."
 msgstr ""
 
@@ -665,3 +693,6 @@ msgstr ""
 #~ "link."
 #~ msgstr ""
 
+#~ msgid "All users on this instance have already been added."
+#~ msgstr ""
+