diff --git a/app/commands.py b/app/commands.py
index b0d1c1964..7b877f2c1 100644
--- a/app/commands.py
+++ b/app/commands.py
@@ -106,7 +106,7 @@ def purge_functional_test_data(user_email_prefix):
     """
     Remove non-seeded functional test data
 
-    users, services, etc. Give an email prefix. Probably "notify-test-preview".
+    users, services, etc. Give an email prefix. Probably "notify-tests-preview".
     """
     users = User.query.filter(User.email_address.like("{}%".format(user_email_prefix))).all()
     for usr in users:
diff --git a/app/dao/services_dao.py b/app/dao/services_dao.py
index 171c1b55f..cf2541f60 100644
--- a/app/dao/services_dao.py
+++ b/app/dao/services_dao.py
@@ -34,6 +34,9 @@ from app.models import (
     Service,
     ServicePermission,
     ServiceSmsSender,
+    ServiceEmailReplyTo,
+    ServiceContactList,
+    ServiceLetterContact,
     Template,
     TemplateHistory,
     TemplateRedacted,
@@ -377,6 +380,9 @@ def delete_service_and_all_associated_db_objects(service):
     _delete_commit(TemplateRedacted.query.filter(TemplateRedacted.template_id.in_(subq)))
 
     _delete_commit(ServiceSmsSender.query.filter_by(service=service))
+    _delete_commit(ServiceEmailReplyTo.query.filter_by(service=service))
+    _delete_commit(ServiceLetterContact.query.filter_by(service=service))
+    _delete_commit(ServiceContactList.query.filter_by(service=service))
     _delete_commit(InvitedUser.query.filter_by(service=service))
     _delete_commit(Permission.query.filter_by(service=service))
     _delete_commit(NotificationHistory.query.filter_by(service=service))
@@ -393,12 +399,14 @@ def delete_service_and_all_associated_db_objects(service):
     list(map(db.session.delete, verify_codes))
     db.session.commit()
     users = [x for x in service.users]
-    map(service.users.remove, users)
-    [service.users.remove(x) for x in users]
+    for user in users:
+        user.organisations = []
+        service.users.remove(user)
     _delete_commit(Service.get_history_model().query.filter_by(id=service.id))
     db.session.delete(service)
     db.session.commit()
-    list(map(db.session.delete, users))
+    for user in users:
+        db.session.delete(user)
     db.session.commit()
 
 
diff --git a/tests/app/dao/test_services_dao.py b/tests/app/dao/test_services_dao.py
index dc43e564d..a0e080bfe 100644
--- a/tests/app/dao/test_services_dao.py
+++ b/tests/app/dao/test_services_dao.py
@@ -663,13 +663,15 @@ def test_create_service_and_history_is_transactional(notify_db_session):
 
 def test_delete_service_and_associated_objects(notify_db_session):
     user = create_user()
-    service = create_service(user=user, service_permissions=None)
+    organisation = create_organisation()
+    service = create_service(user=user, service_permissions=None, organisation=organisation)
     create_user_code(user=user, code='somecode', code_type='email')
     create_user_code(user=user, code='somecode', code_type='sms')
     template = create_template(service=service)
     api_key = create_api_key(service=service)
     create_notification(template=template, api_key=api_key)
     create_invited_user(service=service)
+    user.organisations = [organisation]
 
     assert ServicePermission.query.count() == len((
         SMS_TYPE, EMAIL_TYPE, LETTER_TYPE, INTERNATIONAL_SMS_TYPE, UPLOAD_LETTERS,
@@ -689,6 +691,8 @@ def test_delete_service_and_associated_objects(notify_db_session):
     assert Service.query.count() == 0
     assert Service.get_history_model().query.count() == 0
     assert ServicePermission.query.count() == 0
+    # the organisation hasn't been deleted
+    assert Organisation.query.count() == 1
 
 
 def test_add_existing_user_to_another_service_doesnot_change_old_permissions(notify_db_session):