diff --git a/project/access.py b/project/access.py
index 6e7fb67..62d5d13 100644
--- a/project/access.py
+++ b/project/access.py
@@ -4,9 +4,9 @@ from flask_login import login_user
 from flask_principal import Permission, RoleNeed
 from flask_security import current_user
 from flask_security.utils import FsPermNeed
-from sqlalchemy import and_
+from sqlalchemy import and_, exists
 
-from project import app
+from project import app, db
 from project.models import AdminUnit, AdminUnitMember, Event, PublicStatus, User
 from project.models.admin_unit import AdminUnitMemberRole
 from project.services.admin_unit import get_member_for_admin_unit_by_user_id
@@ -145,16 +145,16 @@ def can_request_event_reference(event):
     if event.public_status != PublicStatus.published:
         return False
 
-    return len(get_admin_units_for_event_reference_request(event)) > 0
-
-
-def get_admin_units_for_event_reference_request(event):
-    return AdminUnit.query.filter(
-        and_(
-            AdminUnit.id != event.admin_unit_id,
-            AdminUnit.incoming_reference_requests_allowed,
+    return db.session.scalar(
+        exists()
+        .where(
+            and_(
+                AdminUnit.id != event.admin_unit_id,
+                AdminUnit.incoming_reference_requests_allowed,
+            )
         )
-    ).all()
+        .select()
+    )
 
 
 def admin_units_the_current_user_is_member_of():
diff --git a/project/api/organization/resources.py b/project/api/organization/resources.py
index ef94690..83ce142 100644
--- a/project/api/organization/resources.py
+++ b/project/api/organization/resources.py
@@ -93,7 +93,7 @@ from project.services.reference import (
     get_reference_outgoing_query,
     get_relation_outgoing_query,
 )
-from project.views.utils import send_mail
+from project.views.utils import get_current_admin_unit_for_api, send_mail
 
 
 class OrganizationResource(BaseResource):
@@ -224,8 +224,19 @@ class OrganizationListResource(BaseResource):
 
         login_api_user()
         include_unverified = can_verify_admin_unit()
+        reference_request_for_admin_unit_id = None
 
-        pagination = get_admin_unit_query(keyword, include_unverified).paginate()
+        if "for_reference_request" in request.args:
+            admin_unit = get_current_admin_unit_for_api()
+
+            if admin_unit:
+                reference_request_for_admin_unit_id = admin_unit.id
+
+        pagination = get_admin_unit_query(
+            keyword,
+            include_unverified,
+            reference_request_for_admin_unit_id=reference_request_for_admin_unit_id,
+        ).paginate()
         return pagination
 
 
diff --git a/project/services/admin_unit.py b/project/services/admin_unit.py
index a506ea4..4079778 100644
--- a/project/services/admin_unit.py
+++ b/project/services/admin_unit.py
@@ -20,6 +20,10 @@ from project.models import (
 )
 from project.services.image import upsert_image_with_data
 from project.services.location import assign_location_values
+from project.services.reference import (
+    get_newest_reference_requests,
+    get_newest_references,
+)
 
 
 def insert_admin_unit_for_user(admin_unit, user, invitation=None):
@@ -175,6 +179,7 @@ def get_admin_unit_query(
     keyword=None,
     include_unverified=False,
     only_verifier=False,
+    reference_request_for_admin_unit_id=None,
 ):
     query = AdminUnit.query
 
@@ -187,6 +192,13 @@ def get_admin_unit_query(
         )
         query = query.filter(only_verifier_filter)
 
+    if reference_request_for_admin_unit_id:
+        request_filter = and_(
+            AdminUnit.id != reference_request_for_admin_unit_id,
+            AdminUnit.incoming_reference_requests_allowed,
+        )
+        query = query.filter(request_filter)
+
     if keyword:
         like_keyword = "%" + keyword + "%"
         order_keyword = keyword + "%"
@@ -384,3 +396,49 @@ def get_admin_units_with_due_delete_request():
 def delete_admin_unit(admin_unit: AdminUnit):
     db.session.delete(admin_unit)
     db.session.commit()
+
+
+def get_admin_unit_suggestions_for_reference_requests(admin_unit, max_choices=5):
+    admin_unit_ids = []
+    admin_unit_choices = []
+    selected_ids = []
+
+    def add_admin_units(admin_units, selected=True):
+        for admin_unit in admin_units:
+            if admin_unit.id in admin_unit_ids:
+                continue
+
+            admin_unit_ids.append(admin_unit.id)
+            admin_unit_choices.append(admin_unit)
+
+            if selected:
+                selected_ids.append(admin_unit.id)
+
+    # Neuste ausgehende Empfehlungsanfragen
+    limit = max_choices - len(admin_unit_ids)
+    reference_requests = get_newest_reference_requests(admin_unit.id, limit)
+    add_admin_units([r.admin_unit for r in reference_requests])
+
+    # Neuste ausgehende Empfehlungen
+    limit = max_choices - len(admin_unit_ids)
+    if limit > 0:
+        references = get_newest_references(admin_unit.id, limit)
+        add_admin_units([r.admin_unit for r in references])
+
+    # Eingehende Beziehungen, die Organisation oder Events automatisch verifizieren
+    limit = max_choices - len(admin_unit_ids)
+    if limit > 0:
+        relations = get_admin_unit_relations_for_reference_requests(
+            admin_unit.id, limit
+        )
+        add_admin_units([r.source_admin_unit for r in relations])
+
+    # Organisationen, die eingehende Empfehlungsanfragen erlauben
+    limit = max_choices - len(admin_unit_ids)
+    if limit > 0:
+        admin_units_for_reference = get_admin_units_for_reference_requests(
+            admin_unit.id, limit
+        )
+        add_admin_units(admin_units_for_reference, False)
+
+    return (admin_unit_choices, selected_ids)
diff --git a/project/templates/event/reference_request.html b/project/templates/event/reference_request.html
index 75c000d..ce5bd0a 100644
--- a/project/templates/event/reference_request.html
+++ b/project/templates/event/reference_request.html
@@ -1,8 +1,57 @@
 {% extends "layout.html" %}
-{% from "_macros.html" import render_field_with_errors, render_field %}
+{% from "_macros.html" import render_field_with_errors, render_field, render_form_styles, render_form_scripts %}
+
 {%- block title -%}
 {{ event.name }}
 {%- endblock -%}
+
+{% block styles %}
+{{ render_form_styles() }}
+{% endblock %}
+
+{% block header_before_site_js %}
+{{ render_form_scripts() }}
+{%- endblock -%}
+
+{% block header %}
+<script>
+    $(function() {
+
+        $('#admin_unit_id').select2({
+            width: '100%',
+            theme: 'bootstrap4',
+            ajax: {
+                url: function (params) {
+                    return '/api/v1/organizations?for_reference_request=1';
+                },
+                dataType: 'json',
+                headers: {"X-OrganizationId": "{{ current_admin_unit.id }}"},
+                delay: 250,
+                cache: true,
+                data: function (params) {
+                    return {
+                        name: params.term,
+                        per_page: 5,
+                        page: params.page || 1
+                    };
+                },
+                processResults: function (data) {
+                    return {
+                        results: data.items.map(p => ({"id": p.id, "text": p.name})),
+                        pagination: {
+                            more: data.has_next
+                        }
+                    };
+                }
+            },
+            placeholder: "{{ _('Enter organization') }}",
+            allowClear: false
+        });
+
+    });
+</script>
+{% endblock %}
+
 {% block content %}
 
 <h1>{{ _('Request reference for event "%(name)s"', name=event.name) }}</h1>
diff --git a/project/views/event.py b/project/views/event.py
index 0a26143..7efecba 100644
--- a/project/views/event.py
+++ b/project/views/event.py
@@ -31,8 +31,7 @@ from project.models import (
 )
 from project.models.event_reference_request import EventReferenceRequest
 from project.services.admin_unit import (
-    get_admin_unit_relations_for_reference_requests,
-    get_admin_units_for_reference_requests,
+    get_admin_unit_suggestions_for_reference_requests,
 )
 from project.services.event import (
     create_ical_events_for_event,
@@ -44,10 +43,6 @@ from project.services.event import (
     update_event,
     upsert_event_category,
 )
-from project.services.reference import (
-    get_newest_reference_requests,
-    get_newest_references,
-)
 from project.utils import get_event_category_name, get_place_str
 from project.views.event_suggestion import send_event_suggestion_review_status_mail
 from project.views.reference_request import handle_request_according_to_relation
@@ -119,48 +114,10 @@ def prepare_form_reference_requests(form, admin_unit):
         form.reference_request_admin_unit_id.choices = []
         return
 
-    max_choices = 5
-    admin_unit_ids = []
-    admin_unit_choices = []
-    selected_ids = []
-
-    def add_admin_units(admin_units, selected=True):
-        for admin_unit in admin_units:
-            if admin_unit.id in admin_unit_ids:
-                continue
-
-            admin_unit_ids.append(admin_unit.id)
-            admin_unit_choices.append(admin_unit)
-
-            if selected:
-                selected_ids.append(admin_unit.id)
-
-    # Neuste ausgehende Empfehlungsanfragen
-    limit = max_choices - len(admin_unit_ids)
-    reference_requests = get_newest_reference_requests(admin_unit.id, limit)
-    add_admin_units([r.admin_unit for r in reference_requests])
-
-    # Neuste ausgehende Empfehlungen
-    limit = max_choices - len(admin_unit_ids)
-    if limit > 0:
-        references = get_newest_references(admin_unit.id, limit)
-        add_admin_units([r.admin_unit for r in references])
-
-    # Eingehende Beziehungen, die Organisation oder Events automatisch verifizieren
-    limit = max_choices - len(admin_unit_ids)
-    if limit > 0:
-        relations = get_admin_unit_relations_for_reference_requests(
-            admin_unit.id, limit
-        )
-        add_admin_units([r.source_admin_unit for r in relations])
-
-    # Organisationen, die eingehende Empfehlungsanfragen erlauben
-    limit = max_choices - len(admin_unit_ids)
-    if limit > 0:
-        admin_units_for_reference = get_admin_units_for_reference_requests(
-            admin_unit.id, limit
-        )
-        add_admin_units(admin_units_for_reference, False)
+    (
+        admin_unit_choices,
+        selected_ids,
+    ) = get_admin_unit_suggestions_for_reference_requests(admin_unit)
 
     form.reference_request_admin_unit_id.choices = sorted(
         [(a.id, a.name) for a in admin_unit_choices],
diff --git a/project/views/reference_request.py b/project/views/reference_request.py
index 0fd7c05..892c940 100644
--- a/project/views/reference_request.py
+++ b/project/views/reference_request.py
@@ -9,7 +9,6 @@ from project.access import (
     can_request_event_reference,
     get_admin_unit_for_manage_or_404,
     get_admin_unit_members_with_permission,
-    get_admin_units_for_event_reference_request,
 )
 from project.forms.reference_request import CreateEventReferenceRequestForm
 from project.models import (
@@ -17,7 +16,11 @@ from project.models import (
     EventReferenceRequest,
     EventReferenceRequestReviewStatus,
 )
-from project.services.admin_unit import get_admin_unit_by_id, get_admin_unit_relation
+from project.services.admin_unit import (
+    get_admin_unit_by_id,
+    get_admin_unit_relation,
+    get_admin_unit_suggestions_for_reference_requests,
+)
 from project.services.reference import (
     create_event_reference_for_request,
     get_reference_requests_incoming_query,
@@ -76,13 +79,24 @@ def event_reference_request_create(event_id):
         abort(401)
 
     form = CreateEventReferenceRequestForm()
-    form.admin_unit_id.choices = sorted(
-        [
-            (admin_unit.id, admin_unit.name)
-            for admin_unit in get_admin_units_for_event_reference_request(event)
-        ],
-        key=lambda admin_unit: admin_unit[1],
-    )
+
+    if form.admin_unit_id.data and form.admin_unit_id.data > 0:
+        admin_unit = get_admin_unit_by_id(form.admin_unit_id.data)
+
+        if admin_unit:
+            form.admin_unit_id.choices = [(admin_unit.id, admin_unit.name)]
+
+    if not form.admin_unit_id.choices:
+        (
+            admin_unit_choices,
+            selected_ids,
+        ) = get_admin_unit_suggestions_for_reference_requests(
+            event.admin_unit, max_choices=1
+        )
+        form.admin_unit_id.choices = [(a.id, a.name) for a in admin_unit_choices]
+        form.admin_unit_id.data = (
+            admin_unit_choices[0].id if len(admin_unit_choices) > 0 else None
+        )
 
     if form.validate_on_submit():
         request = EventReferenceRequest()
diff --git a/tests/api/test_organization.py b/tests/api/test_organization.py
index 10aa1ee..f478655 100644
--- a/tests/api/test_organization.py
+++ b/tests/api/test_organization.py
@@ -23,6 +23,18 @@ def test_list(client, seeder: Seeder, utils: UtilActions):
     utils.get_json_ok(url)
 
 
+def test_list_for_reference_request(client, seeder: Seeder, utils: UtilActions):
+    user_id, admin_unit_id = seeder.setup_api_access()
+    other_user_id = seeder.create_user("other@test.de")
+    other_admin_unit_id = seeder.create_admin_unit(other_user_id, "Other Crew")
+
+    url = utils.get_url("api_v1_organization_list", for_reference_request="1")
+    response = utils.get_json_ok(url, headers={"X-OrganizationId": str(admin_unit_id)})
+
+    assert len(response.json["items"]) == 2
+    assert response.json["items"][1]["id"] == other_admin_unit_id
+
+
 def test_list_unverified(client, app, seeder: Seeder, utils: UtilActions):
     user_id, verified_admin_unit_id = seeder.setup_base(
         email="verified@test.de",