diff --git a/app/celery/nightly_tasks.py b/app/celery/nightly_tasks.py
index 678c9bfa1..f3ee22bf6 100644
--- a/app/celery/nightly_tasks.py
+++ b/app/celery/nightly_tasks.py
@@ -25,7 +25,7 @@ from app.dao.notifications_dao import (
 from app.dao.service_data_retention_dao import (
     fetch_service_data_retention_for_all_services_by_notification_type,
 )
-from app.models import NotificationType, FactProcessingTime
+from app.models import FactProcessingTime, NotificationType
 from app.utils import get_midnight_in_utc
 
 
diff --git a/app/celery/scheduled_tasks.py b/app/celery/scheduled_tasks.py
index 6ec3370cb..314e1f310 100644
--- a/app/celery/scheduled_tasks.py
+++ b/app/celery/scheduled_tasks.py
@@ -38,8 +38,8 @@ from app.models import (
     JOB_STATUS_ERROR,
     JOB_STATUS_IN_PROGRESS,
     JOB_STATUS_PENDING,
-    NotificationType,
     Job,
+    NotificationType,
 )
 from app.notifications.process_notifications import send_notification_to_queue
 
diff --git a/app/commands.py b/app/commands.py
index 26c48c45b..4d084e845 100644
--- a/app/commands.py
+++ b/app/commands.py
@@ -52,11 +52,11 @@ from app.dao.users_dao import (
 from app.models import (
     KEY_TYPE_TEST,
     NOTIFICATION_CREATED,
-    NotificationType,
     AnnualBilling,
     Domain,
     EmailBranding,
     Notification,
+    NotificationType,
     Organization,
     Service,
     Template,
diff --git a/app/dao/fact_billing_dao.py b/app/dao/fact_billing_dao.py
index b2f53dbc2..06b537643 100644
--- a/app/dao/fact_billing_dao.py
+++ b/app/dao/fact_billing_dao.py
@@ -13,11 +13,11 @@ from app.models import (
     KEY_TYPE_TEAM,
     NOTIFICATION_STATUS_TYPES_BILLABLE_SMS,
     NOTIFICATION_STATUS_TYPES_SENT_EMAILS,
-    NotificationType,
     AnnualBilling,
     FactBilling,
     NotificationAllTimeView,
     NotificationHistory,
+    NotificationType,
     Organization,
     Rate,
     Service,
@@ -483,7 +483,9 @@ def get_service_ids_that_need_billing_populated(start_date, end_date):
         .filter(
             NotificationHistory.created_at >= start_date,
             NotificationHistory.created_at <= end_date,
-            NotificationHistory.notification_type.in_([NotificationType.SMS, NotificationType.EMAIL]),
+            NotificationHistory.notification_type.in_(
+                [NotificationType.SMS, NotificationType.EMAIL]
+            ),
             NotificationHistory.billable_units != 0,
         )
         .distinct()
diff --git a/app/dao/inbound_sms_dao.py b/app/dao/inbound_sms_dao.py
index 2b5767caa..5143746d9 100644
--- a/app/dao/inbound_sms_dao.py
+++ b/app/dao/inbound_sms_dao.py
@@ -6,9 +6,9 @@ from sqlalchemy.orm import aliased
 from app import db
 from app.dao.dao_utils import autocommit
 from app.models import (
-    NotificationType,
     InboundSms,
     InboundSmsHistory,
+    NotificationType,
     Service,
     ServiceDataRetention,
 )
diff --git a/app/dao/notifications_dao.py b/app/dao/notifications_dao.py
index c903de270..42ac8671c 100644
--- a/app/dao/notifications_dao.py
+++ b/app/dao/notifications_dao.py
@@ -26,10 +26,10 @@ from app.models import (
     NOTIFICATION_SENDING,
     NOTIFICATION_SENT,
     NOTIFICATION_TEMPORARY_FAILURE,
-    NotificationType,
     FactNotificationStatus,
     Notification,
     NotificationHistory,
+    NotificationType,
 )
 from app.utils import (
     escape_special_characters,
@@ -444,7 +444,9 @@ def dao_timeout_notifications(cutoff_time, limit=100000):
         Notification.query.filter(
             Notification.created_at < cutoff_time,
             Notification.status.in_(current_statuses),
-            Notification.notification_type.in_([NotificationType.SMS, NotificationType.EMAIL]),
+            Notification.notification_type.in_(
+                [NotificationType.SMS, NotificationType.EMAIL]
+            ),
         )
         .limit(limit)
         .all()
@@ -506,7 +508,9 @@ def dao_get_notifications_by_recipient_or_reference(
         normalised = "".join(search_term.split()).lower()
 
     else:
-        raise TypeError(f"Notification type must be {NotificationType.EMAIL}, {NotificationType.SMS}, or None")
+        raise TypeError(
+            f"Notification type must be {NotificationType.EMAIL}, {NotificationType.SMS}, or None"
+        )
 
     normalised = escape_special_characters(normalised)
     search_term = escape_special_characters(search_term)
diff --git a/app/dao/provider_details_dao.py b/app/dao/provider_details_dao.py
index 3497e8398..270f8731e 100644
--- a/app/dao/provider_details_dao.py
+++ b/app/dao/provider_details_dao.py
@@ -6,8 +6,8 @@ from sqlalchemy import asc, desc, func
 from app import db
 from app.dao.dao_utils import autocommit
 from app.models import (
-    NotificationType,
     FactBilling,
+    NotificationType,
     ProviderDetails,
     ProviderDetailsHistory,
     User,
diff --git a/app/dao/uploads_dao.py b/app/dao/uploads_dao.py
index 6ef166edd..200d41805 100644
--- a/app/dao/uploads_dao.py
+++ b/app/dao/uploads_dao.py
@@ -8,10 +8,10 @@ from app import db
 from app.models import (
     JOB_STATUS_CANCELLED,
     JOB_STATUS_SCHEDULED,
-    NotificationType,
     NOTIFICATION_CANCELLED,
     Job,
     Notification,
+    NotificationType,
     ServiceDataRetention,
     Template,
 )
diff --git a/app/models.py b/app/models.py
index 92b2871a6..29fde4ffd 100644
--- a/app/models.py
+++ b/app/models.py
@@ -44,6 +44,8 @@ class NotificationType(Enum):
 NORMAL = "normal"
 PRIORITY = "priority"
 TEMPLATE_PROCESS_TYPE = [NORMAL, PRIORITY]
+
+
 class TemplateProcessType(Enum):
     # TODO: Should Template.process_type be changed to use this?
     NORMAL = "normal"
@@ -54,6 +56,8 @@ SMS_AUTH_TYPE = "sms_auth"
 EMAIL_AUTH_TYPE = "email_auth"
 WEBAUTHN_AUTH_TYPE = "webauthn_auth"
 USER_AUTH_TYPES = [SMS_AUTH_TYPE, EMAIL_AUTH_TYPE, WEBAUTHN_AUTH_TYPE]
+
+
 class UserAuthType(Enum):
     # TODO: Should User.auth_type be changed to use this?
     SMS = "sms_auth"
@@ -64,10 +68,13 @@ class UserAuthType(Enum):
 DELIVERY_STATUS_CALLBACK_TYPE = "delivery_status"
 COMPLAINT_CALLBACK_TYPE = "complaint"
 SERVICE_CALLBACK_TYPES = [DELIVERY_STATUS_CALLBACK_TYPE, COMPLAINT_CALLBACK_TYPE]
-class ServiceCallbackType(Enum):
-    # TODO: Should ServiceCallbackApi.callback_type be changed to use this?
-    DELIVERY_STATUS = "delivery_status"
-    COMPLAINT = "complaint"
+
+
+# class ServiceCallbackType(Enum):
+#     # TODO: Should ServiceCallbackApi.callback_type be changed to use this?
+#     DELIVERY_STATUS = "delivery_status"
+#     COMPLAINT = "complaint"
+
 
 def filter_null_value_fields(obj):
     return dict(filter(lambda x: x[1] is not None, obj.items()))
@@ -287,6 +294,8 @@ BRANDING_ORG = "org"
 BRANDING_BOTH = "both"
 BRANDING_ORG_BANNER = "org_banner"
 BRANDING_TYPES = [BRANDING_ORG, BRANDING_BOTH, BRANDING_ORG_BANNER]
+
+
 class BrandingType(Enum):
     # TODO: Should EmailBranding.branding_type be changed to use this?
     GOVUK = "govuk"  # Deprecated outside migrations
@@ -295,7 +304,6 @@ class BrandingType(Enum):
     ORG_BANNER = "org_banner"
 
 
-
 class BrandingTypes(db.Model):
     __tablename__ = "branding_type"
     name = db.Column(db.String(255), primary_key=True)
@@ -805,10 +813,12 @@ class ServicePermission(db.Model):
 # MOBILE_TYPE = "mobile"
 # EMAIL_TYPE = "email"
 
+
 class GuestListRecipientType(Enum):
     MOBILE = "mobile"
     EMAIL = "email"
 
+
 guest_list_recipient_types = db.Enum(GuestListRecipientType, name="recipient_type")
 
 
@@ -999,6 +1009,8 @@ class ApiKey(db.Model, Versioned):
 KEY_TYPE_NORMAL = "normal"
 KEY_TYPE_TEAM = "team"
 KEY_TYPE_TEST = "test"
+
+
 class KeyType(Enum):
     # TODO: Should Key Types be rewritten to use this?
     NORMAL = "normal"
@@ -1006,7 +1018,6 @@ class KeyType(Enum):
     TEST = "test"
 
 
-
 class KeyTypes(db.Model):
     __tablename__ = "key_types"
 
@@ -1100,7 +1111,9 @@ class TemplateBase(db.Model):
 
     id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
     name = db.Column(db.String(255), nullable=False)
-    template_type = db.Column(db.Enum(TemplateType, name="template_type"), nullable=False)
+    template_type = db.Column(
+        db.Enum(TemplateType, name="template_type"), nullable=False
+    )
     created_at = db.Column(
         db.DateTime, nullable=False, default=datetime.datetime.utcnow
     )
@@ -1184,7 +1197,9 @@ class TemplateBase(db.Model):
             "created_by": self.created_by.email_address,
             "version": self.version,
             "body": self.content,
-            "subject": self.subject if self.template_type == TemplateType.EMAIL else None,
+            "subject": self.subject
+            if self.template_type == TemplateType.EMAIL
+            else None,
             "name": self.name,
             "personalisation": {
                 key: {
@@ -1355,6 +1370,8 @@ JOB_STATUS_TYPES = [
     JOB_STATUS_SENT_TO_DVLA,
     JOB_STATUS_ERROR,
 ]
+
+
 class JobStatusType(Enum):
     # TODO: Should Job.job_status be changed to use this?
     PENDING = "pending"
@@ -1850,8 +1867,12 @@ class Notification(db.Model):
         serialized = {
             "id": self.id,
             "reference": self.client_reference,
-            "email_address": self.to if self.notification_type == NotificationType.EMAIL else None,
-            "phone_number": self.to if self.notification_type == NotificationType.SMS else None,
+            "email_address": self.to
+            if self.notification_type == NotificationType.EMAIL
+            else None,
+            "phone_number": self.to
+            if self.notification_type == NotificationType.SMS
+            else None,
             "line_1": None,
             "line_2": None,
             "line_3": None,
diff --git a/app/notifications/process_notifications.py b/app/notifications/process_notifications.py
index 8d02795f1..24a24bc8d 100644
--- a/app/notifications/process_notifications.py
+++ b/app/notifications/process_notifications.py
@@ -122,7 +122,9 @@ def persist_notification(
         notification.phone_prefix = recipient_info.country_prefix
         notification.rate_multiplier = recipient_info.billable_units
     elif notification_type == NotificationType.EMAIL:
-        current_app.logger.info(f"Persisting notification with type: {NotificationType.EMAIL}")
+        current_app.logger.info(
+            f"Persisting notification with type: {NotificationType.EMAIL}"
+        )
         redis_store.set(
             f"email-address-{notification.id}",
             format_email_address(notification.to),
diff --git a/app/notifications/receive_notifications.py b/app/notifications/receive_notifications.py
index 04e652ebd..c1031417b 100644
--- a/app/notifications/receive_notifications.py
+++ b/app/notifications/receive_notifications.py
@@ -125,4 +125,6 @@ def fetch_potential_service(inbound_number, provider_name):
 
 def has_inbound_sms_permissions(permissions):
     str_permissions = [p.permission for p in permissions]
-    return {ServicePermissionType.INBOUND_SMS, ServicePermissionType.SMS}.issubset(set(str_permissions))
+    return {ServicePermissionType.INBOUND_SMS, ServicePermissionType.SMS}.issubset(
+        set(str_permissions)
+    )
diff --git a/app/service/rest.py b/app/service/rest.py
index ec7002990..355978b5d 100644
--- a/app/service/rest.py
+++ b/app/service/rest.py
@@ -643,10 +643,14 @@ def get_guest_list(service_id):
     guest_list = dao_fetch_service_guest_list(service.id)
     return jsonify(
         email_addresses=[
-            item.recipient for item in guest_list if item.recipient_type == GuestListRecipientType.EMAIL
+            item.recipient
+            for item in guest_list
+            if item.recipient_type == GuestListRecipientType.EMAIL
         ],
         phone_numbers=[
-            item.recipient for item in guest_list if item.recipient_type == GuestListRecipientType.MOBILE
+            item.recipient
+            for item in guest_list
+            if item.recipient_type == GuestListRecipientType.MOBILE
         ],
     )
 
diff --git a/app/service/utils.py b/app/service/utils.py
index c323bdc06..3b21b90ee 100644
--- a/app/service/utils.py
+++ b/app/service/utils.py
@@ -20,8 +20,12 @@ def get_guest_list_objects(service_id, request_json):
     return [
         ServiceGuestList.from_string(service_id, type, recipient)
         for type, recipient in (
-            get_recipients_from_request(request_json, "phone_numbers", GuestListRecipientType.MOBILE)
-            + get_recipients_from_request(request_json, "email_addresses", GuestListRecipientType.EMAIL)
+            get_recipients_from_request(
+                request_json, "phone_numbers", GuestListRecipientType.MOBILE
+            )
+            + get_recipients_from_request(
+                request_json, "email_addresses", GuestListRecipientType.EMAIL
+            )
         )
     ]
 
diff --git a/app/user/rest.py b/app/user/rest.py
index 3192613e6..278eaf396 100644
--- a/app/user/rest.py
+++ b/app/user/rest.py
@@ -33,7 +33,13 @@ from app.dao.users_dao import (
     use_user_code,
 )
 from app.errors import InvalidRequest, register_errors
-from app.models import KEY_TYPE_NORMAL, Notification, NotificationType, Permission, Service, TemplateType
+from app.models import (
+    KEY_TYPE_NORMAL,
+    NotificationType,
+    Permission,
+    Service,
+    TemplateType,
+)
 from app.notifications.process_notifications import (
     persist_notification,
     send_notification_to_queue,
diff --git a/app/utils.py b/app/utils.py
index e922a34f4..eea303250 100644
--- a/app/utils.py
+++ b/app/utils.py
@@ -46,9 +46,7 @@ def get_template_instance(template, values):
     return {
         TemplateType.SMS: SMSMessageTemplate,
         TemplateType.EMAIL: HTMLEmailTemplate,
-    }[
-        template["template_type"]
-    ](template, values)
+    }[template["template_type"]](template, values)
 
 
 def get_midnight_in_utc(date):
@@ -80,7 +78,7 @@ def get_month_from_utc_column(column):
 
 
 def get_public_notify_type_text(notify_type, plural=False):
-    from app.models import NotificationType, UPLOAD_DOCUMENT
+    from app.models import UPLOAD_DOCUMENT, NotificationType
 
     notify_type_text = notify_type
     if notify_type == NotificationType.SMS:
diff --git a/tests/app/celery/test_nightly_tasks.py b/tests/app/celery/test_nightly_tasks.py
index 63f4b22fd..9caef3532 100644
--- a/tests/app/celery/test_nightly_tasks.py
+++ b/tests/app/celery/test_nightly_tasks.py
@@ -17,7 +17,7 @@ from app.celery.nightly_tasks import (
     save_daily_notification_processing_time,
     timeout_notifications,
 )
-from app.models import EMAIL_TYPE, SMS_TYPE, FactProcessingTime, Job
+from app.models import FactProcessingTime, Job, NotificationType
 from tests.app.db import (
     create_job,
     create_notification,
@@ -95,10 +95,10 @@ def test_will_remove_csv_files_for_jobs_older_than_retention_period(
     service_1 = create_service(service_name="service 1")
     service_2 = create_service(service_name="service 2")
     create_service_data_retention(
-        service=service_1, notification_type=SMS_TYPE, days_of_retention=3
+        service=service_1, notification_type=NotificationType.SMS, days_of_retention=3
     )
     create_service_data_retention(
-        service=service_2, notification_type=EMAIL_TYPE, days_of_retention=30
+        service=service_2, notification_type=NotificationType.EMAIL, days_of_retention=30
     )
     sms_template_service_1 = create_template(service=service_1)
     email_template_service_1 = create_template(service=service_1, template_type="email")
diff --git a/tests/app/celery/test_reporting_tasks.py b/tests/app/celery/test_reporting_tasks.py
index 2dee56c27..70eb44b8b 100644
--- a/tests/app/celery/test_reporting_tasks.py
+++ b/tests/app/celery/test_reporting_tasks.py
@@ -14,15 +14,14 @@ from app.celery.reporting_tasks import (
 from app.config import QueueNames
 from app.dao.fact_billing_dao import get_rate
 from app.models import (
-    EMAIL_TYPE,
     KEY_TYPE_NORMAL,
     KEY_TYPE_TEAM,
     KEY_TYPE_TEST,
     NOTIFICATION_TYPES,
-    SMS_TYPE,
     FactBilling,
     FactNotificationStatus,
     Notification,
+    NotificationType,
 )
 from tests.app.db import (
     create_notification,
@@ -36,9 +35,9 @@ from tests.app.db import (
 def mocker_get_rate(
     non_letter_rates, notification_type, local_date, rate_multiplier=None
 ):
-    if notification_type == SMS_TYPE:
+    if notification_type == NotificationType.SMS:
         return Decimal(1.33)
-    elif notification_type == EMAIL_TYPE:
+    elif notification_type == NotificationType.EMAIL:
         return Decimal(0)
 
 
@@ -83,7 +82,7 @@ def test_create_nightly_notification_status_triggers_tasks(
         kwargs={
             "service_id": sample_service.id,
             "process_day": "2019-07-31",
-            "notification_type": SMS_TYPE,
+            "notification_type": NotificationType.SMS,
         },
         queue=QueueNames.REPORTING,
     )
@@ -94,8 +93,8 @@ def test_create_nightly_notification_status_triggers_tasks(
     "notification_date, expected_types_aggregated",
     [
         ("2019-08-01", set()),
-        ("2019-07-31", {EMAIL_TYPE, SMS_TYPE}),
-        ("2019-07-28", {EMAIL_TYPE, SMS_TYPE}),
+        ("2019-07-31", {NotificationType.EMAIL, NotificationType.SMS}),
+        ("2019-07-28", {NotificationType.EMAIL, NotificationType.SMS}),
         ("2019-07-21", set()),
     ],
 )
@@ -148,7 +147,7 @@ def test_create_nightly_billing_for_day_checks_history(
     assert len(records) == 1
 
     record = records[0]
-    assert record.notification_type == SMS_TYPE
+    assert record.notification_type == NotificationType.SMS
     assert record.notifications_sent == 2
 
 
@@ -321,14 +320,14 @@ def test_create_nightly_billing_for_day_null_sent_by_sms(
 
 def test_get_rate_for_sms_and_email(notify_db_session):
     non_letter_rates = [
-        create_rate(datetime(2017, 12, 1), 0.15, SMS_TYPE),
-        create_rate(datetime(2017, 12, 1), 0, EMAIL_TYPE),
+        create_rate(datetime(2017, 12, 1), 0.15, NotificationType.SMS),
+        create_rate(datetime(2017, 12, 1), 0, NotificationType.EMAIL),
     ]
 
-    rate = get_rate(non_letter_rates, SMS_TYPE, date(2018, 1, 1))
+    rate = get_rate(non_letter_rates, NotificationType.SMS, date(2018, 1, 1))
     assert rate == Decimal(0.15)
 
-    rate = get_rate(non_letter_rates, EMAIL_TYPE, date(2018, 1, 1))
+    rate = get_rate(non_letter_rates, NotificationType.EMAIL, date(2018, 1, 1))
     assert rate == Decimal(0)
 
 
diff --git a/tests/app/celery/test_tasks.py b/tests/app/celery/test_tasks.py
index 41c613563..b9e08ce30 100644
--- a/tests/app/celery/test_tasks.py
+++ b/tests/app/celery/test_tasks.py
@@ -30,15 +30,15 @@ from app.celery.tasks import (
 from app.config import QueueNames
 from app.dao import jobs_dao, service_email_reply_to_dao, service_sms_sender_dao
 from app.models import (
-    EMAIL_TYPE,
     JOB_STATUS_ERROR,
     JOB_STATUS_FINISHED,
     JOB_STATUS_IN_PROGRESS,
     KEY_TYPE_NORMAL,
     NOTIFICATION_CREATED,
-    SMS_TYPE,
     Job,
     Notification,
+    NotificationType,
+    TemplateType,
 )
 from app.serialised_models import SerialisedService, SerialisedTemplate
 from app.utils import DATETIME_FORMAT
@@ -305,8 +305,8 @@ def test_should_process_all_sms_job(sample_job_with_placeholdered_template, mock
 @pytest.mark.parametrize(
     "template_type, expected_function, expected_queue",
     [
-        (SMS_TYPE, "save_sms", "database-tasks"),
-        (EMAIL_TYPE, "save_email", "database-tasks"),
+        (TemplateType.SMS, "save_sms", "database-tasks"),
+        (TemplateType.EMAIL, "save_email", "database-tasks"),
     ],
 )
 def test_process_row_sends_letter_task(
@@ -362,7 +362,7 @@ def test_process_row_when_sender_id_is_provided(mocker, fake_uuid):
     mocker.patch("app.celery.tasks.create_uuid", return_value="noti_uuid")
     task_mock = mocker.patch("app.celery.tasks.save_sms.apply_async")
     encrypt_mock = mocker.patch("app.celery.tasks.encryption.encrypt")
-    template = Mock(id="template_id", template_type=SMS_TYPE)
+    template = Mock(id="template_id", template_type=TemplateType.SMS)
     job = Mock(id="job_id", template_version="temp_vers")
     service = Mock(id="service_id", research_mode=False)
 
@@ -1384,8 +1384,8 @@ def test_process_incomplete_jobs_sets_status_to_in_progress_and_resets_processin
 def test_save_api_email_or_sms(mocker, sample_service, notification_type):
     template = (
         create_template(sample_service)
-        if notification_type == SMS_TYPE
-        else create_template(sample_service, template_type=EMAIL_TYPE)
+        if notification_type == NotificationType.SMS
+        else create_template(sample_service, template_type=TemplateType.EMAIL)
     )
     mock_provider_task = mocker.patch(
         f"app.celery.provider_tasks.deliver_{notification_type}.apply_async"
@@ -1407,7 +1407,7 @@ def test_save_api_email_or_sms(mocker, sample_service, notification_type):
         "created_at": datetime.utcnow().strftime(DATETIME_FORMAT),
     }
 
-    if notification_type == EMAIL_TYPE:
+    if notification_type == NotificationType.EMAIL:
         data.update({"to": "jane.citizen@example.com"})
         expected_queue = QueueNames.SEND_EMAIL
     else:
@@ -1417,7 +1417,7 @@ def test_save_api_email_or_sms(mocker, sample_service, notification_type):
     encrypted = encryption.encrypt(data)
 
     assert len(Notification.query.all()) == 0
-    if notification_type == EMAIL_TYPE:
+    if notification_type == NotificationType.EMAIL:
         save_api_email(encrypted_notification=encrypted)
     else:
         save_api_sms(encrypted_notification=encrypted)
@@ -1436,8 +1436,8 @@ def test_save_api_email_dont_retry_if_notification_already_exists(
 ):
     template = (
         create_template(sample_service)
-        if notification_type == SMS_TYPE
-        else create_template(sample_service, template_type=EMAIL_TYPE)
+        if notification_type == NotificationType.SMS
+        else create_template(sample_service, template_type=TemplateType.EMAIL)
     )
     mock_provider_task = mocker.patch(
         f"app.celery.provider_tasks.deliver_{notification_type}.apply_async"
@@ -1459,7 +1459,7 @@ def test_save_api_email_dont_retry_if_notification_already_exists(
         "created_at": datetime.utcnow().strftime(DATETIME_FORMAT),
     }
 
-    if notification_type == EMAIL_TYPE:
+    if notification_type == NotificationType.EMAIL:
         data.update({"to": "jane.citizen@example.com"})
         expected_queue = QueueNames.SEND_EMAIL
     else:
@@ -1469,14 +1469,14 @@ def test_save_api_email_dont_retry_if_notification_already_exists(
     encrypted = encryption.encrypt(data)
     assert len(Notification.query.all()) == 0
 
-    if notification_type == EMAIL_TYPE:
+    if notification_type == NotificationType.EMAIL:
         save_api_email(encrypted_notification=encrypted)
     else:
         save_api_sms(encrypted_notification=encrypted)
     notifications = Notification.query.all()
     assert len(notifications) == 1
     # call the task again with the same notification
-    if notification_type == EMAIL_TYPE:
+    if notification_type == NotificationType.EMAIL:
         save_api_email(encrypted_notification=encrypted)
     else:
         save_api_sms(encrypted_notification=encrypted)
diff --git a/tests/app/conftest.py b/tests/app/conftest.py
index 249dcdcf8..db1b3914c 100644
--- a/tests/app/conftest.py
+++ b/tests/app/conftest.py
@@ -19,14 +19,13 @@ from app.dao.templates_dao import dao_create_template
 from app.dao.users_dao import create_secret_code, create_user_code
 from app.history_meta import create_history
 from app.models import (
-    EMAIL_TYPE,
     KEY_TYPE_NORMAL,
     KEY_TYPE_TEAM,
     KEY_TYPE_TEST,
     NOTIFICATION_STATUS_TYPES_COMPLETED,
     SERVICE_PERMISSION_TYPES,
-    SMS_TYPE,
     ApiKey,
+    GuestListRecipientType,
     InvitedUser,
     Job,
     Notification,
@@ -38,8 +37,10 @@ from app.models import (
     Service,
     ServiceEmailReplyTo,
     ServiceGuestList,
+    ServicePermissionType,
     Template,
     TemplateHistory,
+    TemplateType,
 )
 from tests import create_admin_authorization_header
 from tests.app.db import (
@@ -246,7 +247,7 @@ def _sample_service_full_permissions(notify_db_session):
 @pytest.fixture(scope="function")
 def sample_template(sample_user):
     service = create_service(
-        service_permissions=[EMAIL_TYPE, SMS_TYPE], check_if_service_exists=True
+        service_permissions=[ServicePermissionType.EMAIL, ServicePermissionType.SMS], check_if_service_exists=True
     )
 
     data = {
@@ -268,9 +269,9 @@ def sample_template(sample_user):
 @pytest.fixture(scope="function")
 def sample_template_without_sms_permission(notify_db_session):
     service = create_service(
-        service_permissions=[EMAIL_TYPE], check_if_service_exists=True
+        service_permissions=[ServicePermissionType.EMAIL], check_if_service_exists=True
     )
-    return create_template(service, template_type=SMS_TYPE)
+    return create_template(service, template_type=TemplateType.SMS)
 
 
 @pytest.fixture(scope="function")
@@ -293,12 +294,12 @@ def sample_sms_template_with_html(sample_service):
 def sample_email_template(sample_user):
     service = create_service(
         user=sample_user,
-        service_permissions=[EMAIL_TYPE, SMS_TYPE],
+        service_permissions=[ServicePermissionType.EMAIL, ServicePermissionType.SMS],
         check_if_service_exists=True,
     )
     data = {
         "name": "Email Template Name",
-        "template_type": EMAIL_TYPE,
+        "template_type": TemplateType.EMAIL,
         "content": "This is a template",
         "service": service,
         "created_by": sample_user,
@@ -312,16 +313,16 @@ def sample_email_template(sample_user):
 @pytest.fixture(scope="function")
 def sample_template_without_email_permission(notify_db_session):
     service = create_service(
-        service_permissions=[SMS_TYPE], check_if_service_exists=True
+        service_permissions=[ServicePermissionType.SMS], check_if_service_exists=True
     )
-    return create_template(service, template_type=EMAIL_TYPE)
+    return create_template(service, template_type=TemplateType.EMAIL)
 
 
 @pytest.fixture(scope="function")
 def sample_email_template_with_placeholders(sample_service):
     return create_template(
         sample_service,
-        template_type=EMAIL_TYPE,
+        template_type=TemplateType.EMAIL,
         subject="((name))",
         content="Hello ((name))\nThis is an email from GOV.UK",
     )
@@ -331,7 +332,7 @@ def sample_email_template_with_placeholders(sample_service):
 def sample_email_template_with_html(sample_service):
     return create_template(
         sample_service,
-        template_type=EMAIL_TYPE,
+        template_type=TemplateType.EMAIL,
         subject="((name)) <em>some HTML</em>",
         content="Hello ((name))\nThis is an email from GOV.UK with <em>some HTML</em>",
     )
@@ -480,7 +481,7 @@ def sample_notification(notify_db_session):
 def sample_email_notification(notify_db_session):
     created_at = datetime.utcnow()
     service = create_service(check_if_service_exists=True)
-    template = create_template(service, template_type=EMAIL_TYPE)
+    template = create_template(service, template_type=TemplateType.EMAIL)
     job = create_job(template)
 
     notification_id = uuid.uuid4()
@@ -843,7 +844,7 @@ def notify_service(notify_db_session, sample_user):
 def sample_service_guest_list(notify_db_session):
     service = create_service(check_if_service_exists=True)
     guest_list_user = ServiceGuestList.from_string(
-        service.id, EMAIL_TYPE, "guest_list_user@digital.fake.gov"
+        service.id, GuestListRecipientType.EMAIL, "guest_list_user@digital.fake.gov"
     )
 
     notify_db_session.add(guest_list_user)
diff --git a/tests/app/dao/test_fact_notification_status_dao.py b/tests/app/dao/test_fact_notification_status_dao.py
index a38d3e3ec..c5586be34 100644
--- a/tests/app/dao/test_fact_notification_status_dao.py
+++ b/tests/app/dao/test_fact_notification_status_dao.py
@@ -18,7 +18,6 @@ from app.dao.fact_notification_status_dao import (
     update_fact_notification_status,
 )
 from app.models import (
-    EMAIL_TYPE,
     KEY_TYPE_TEAM,
     KEY_TYPE_TEST,
     NOTIFICATION_CREATED,
@@ -30,8 +29,8 @@ from app.models import (
     NOTIFICATION_SENT,
     NOTIFICATION_TECHNICAL_FAILURE,
     NOTIFICATION_TEMPORARY_FAILURE,
-    SMS_TYPE,
     FactNotificationStatus,
+    TemplateType,
 )
 from tests.app.db import (
     create_ft_notification_status,
@@ -167,9 +166,9 @@ def test_fetch_notification_status_for_service_for_today_and_7_previous_days(
     notify_db_session,
 ):
     service_1 = create_service(service_name="service_1")
-    sms_template = create_template(service=service_1, template_type=SMS_TYPE)
-    sms_template_2 = create_template(service=service_1, template_type=SMS_TYPE)
-    email_template = create_template(service=service_1, template_type=EMAIL_TYPE)
+    sms_template = create_template(service=service_1, template_type=TemplateType.SMS)
+    sms_template_2 = create_template(service=service_1, template_type=TemplateType.SMS)
+    email_template = create_template(service=service_1, template_type=TemplateType.EMAIL)
 
     create_ft_notification_status(date(2018, 10, 29), "sms", service_1, count=10)
     create_ft_notification_status(date(2018, 10, 25), "sms", service_1, count=8)
@@ -222,15 +221,15 @@ def test_fetch_notification_status_by_template_for_service_for_today_and_7_previ
 ):
     service_1 = create_service(service_name="service_1")
     sms_template = create_template(
-        template_name="sms Template 1", service=service_1, template_type=SMS_TYPE
+        template_name="sms Template 1", service=service_1, template_type=TemplateType.SMS
     )
     sms_template_2 = create_template(
-        template_name="sms Template 2", service=service_1, template_type=SMS_TYPE
+        template_name="sms Template 2", service=service_1, template_type=TemplateType.SMS
     )
-    email_template = create_template(service=service_1, template_type=EMAIL_TYPE)
+    email_template = create_template(service=service_1, template_type=TemplateType.EMAIL)
 
     # create unused email template
-    create_template(service=service_1, template_type=EMAIL_TYPE)
+    create_template(service=service_1, template_type=TemplateType.EMAIL)
 
     create_ft_notification_status(date(2018, 10, 29), "sms", service_1, count=10)
     create_ft_notification_status(date(2018, 10, 29), "sms", service_1, count=11)
@@ -323,8 +322,8 @@ def test_fetch_notification_status_totals_for_all_services_works_in_est(
     notify_db_session,
 ):
     service_1 = create_service(service_name="service_1")
-    sms_template = create_template(service=service_1, template_type=SMS_TYPE)
-    email_template = create_template(service=service_1, template_type=EMAIL_TYPE)
+    sms_template = create_template(service=service_1, template_type=TemplateType.SMS)
+    email_template = create_template(service=service_1, template_type=TemplateType.EMAIL)
 
     create_notification(
         sms_template, created_at=datetime(2018, 4, 20, 12, 0, 0), status="delivered"
@@ -367,8 +366,8 @@ def test_fetch_notification_status_totals_for_all_services_works_in_est(
 def set_up_data():
     service_2 = create_service(service_name="service_2")
     service_1 = create_service(service_name="service_1")
-    sms_template = create_template(service=service_1, template_type=SMS_TYPE)
-    email_template = create_template(service=service_1, template_type=EMAIL_TYPE)
+    sms_template = create_template(service=service_1, template_type=TemplateType.SMS)
+    email_template = create_template(service=service_1, template_type=TemplateType.EMAIL)
     create_ft_notification_status(date(2018, 10, 24), "sms", service_1, count=8)
     create_ft_notification_status(date(2018, 10, 29), "sms", service_1, count=10)
     create_ft_notification_status(
diff --git a/tests/app/dao/test_service_guest_list_dao.py b/tests/app/dao/test_service_guest_list_dao.py
index 5d8e97bd3..3fdd88227 100644
--- a/tests/app/dao/test_service_guest_list_dao.py
+++ b/tests/app/dao/test_service_guest_list_dao.py
@@ -5,7 +5,7 @@ from app.dao.service_guest_list_dao import (
     dao_fetch_service_guest_list,
     dao_remove_service_guest_list,
 )
-from app.models import EMAIL_TYPE, ServiceGuestList
+from app.models import GuestListRecipientType, ServiceGuestList
 from tests.app.db import create_service
 
 
@@ -21,7 +21,7 @@ def test_fetch_service_guest_list_ignores_other_service(sample_service_guest_lis
 
 def test_add_and_commit_guest_list_contacts_saves_data(sample_service):
     guest_list = ServiceGuestList.from_string(
-        sample_service.id, EMAIL_TYPE, "foo@example.com"
+        sample_service.id, GuestListRecipientType.EMAIL, "foo@example.com"
     )
 
     dao_add_and_commit_guest_list_contacts([guest_list])
@@ -37,10 +37,10 @@ def test_remove_service_guest_list_only_removes_for_my_service(notify_db_session
     dao_add_and_commit_guest_list_contacts(
         [
             ServiceGuestList.from_string(
-                service_1.id, EMAIL_TYPE, "service1@example.com"
+                service_1.id, GuestListRecipientType.EMAIL, "service1@example.com"
             ),
             ServiceGuestList.from_string(
-                service_2.id, EMAIL_TYPE, "service2@example.com"
+                service_2.id, GuestListRecipientType.EMAIL, "service2@example.com"
             ),
         ]
     )
diff --git a/tests/app/db.py b/tests/app/db.py
index 56a33335f..b8bcbc539 100644
--- a/tests/app/db.py
+++ b/tests/app/db.py
@@ -27,10 +27,7 @@ from app.dao.services_dao import dao_add_user_to_service, dao_create_service
 from app.dao.templates_dao import dao_create_template, dao_update_template
 from app.dao.users_dao import save_model_user
 from app.models import (
-    EMAIL_TYPE,
     KEY_TYPE_NORMAL,
-    MOBILE_TYPE,
-    SMS_TYPE,
     AnnualBilling,
     ApiKey,
     Complaint,
@@ -39,6 +36,7 @@ from app.models import (
     FactBilling,
     FactNotificationStatus,
     FactProcessingTime,
+    GuestListRecipientType,
     InboundNumber,
     InboundSms,
     InvitedOrganizationUser,
@@ -55,9 +53,11 @@ from app.models import (
     ServiceGuestList,
     ServiceInboundApi,
     ServicePermission,
+    ServicePermissionType,
     ServiceSmsSender,
     Template,
     TemplateFolder,
+    TemplateType,
     User,
     WebauthnCredential,
 )
@@ -193,7 +193,7 @@ def create_service_with_defined_sms_sender(sms_sender_value="1234567", *args, **
 
 def create_template(
     service,
-    template_type=SMS_TYPE,
+    template_type=TemplateType.SMS,
     template_name=None,
     subject="Template subject",
     content="Dear Sir/Madam, Hello. Yours Truly, The Government.",
@@ -215,7 +215,7 @@ def create_template(
         "folder": folder,
         "process_type": process_type,
     }
-    if template_type != SMS_TYPE:
+    if template_type != TemplateType.SMS:
         data["subject"] = subject
     template = Template(**data)
     dao_create_template(template)
@@ -262,7 +262,7 @@ def create_notification(
     if to_field is None:
         to_field = (
             "+447700900855"
-            if template.template_type == SMS_TYPE
+            if template.template_type == TemplateType.SMS
             else "test@example.com"
         )
 
@@ -415,9 +415,10 @@ def create_job(
     return job
 
 
-def create_service_permission(service_id, permission=EMAIL_TYPE):
+def create_service_permission(service_id, permission=ServicePermissionType.EMAIL):
     dao_add_service_permission(
-        service_id if service_id else create_service().id, permission
+        service_id if service_id else create_service().id,
+        permission,
     )
 
     service_permissions = ServicePermission.query.all()
@@ -724,15 +725,15 @@ def create_process_time(
 def create_service_guest_list(service, email_address=None, mobile_number=None):
     if email_address:
         guest_list_user = ServiceGuestList.from_string(
-            service.id, EMAIL_TYPE, email_address
+            service.id, GuestListRecipientType.EMAIL, email_address
         )
     elif mobile_number:
         guest_list_user = ServiceGuestList.from_string(
-            service.id, MOBILE_TYPE, mobile_number
+            service.id, GuestListRecipientType.MOBILE, mobile_number
         )
     else:
         guest_list_user = ServiceGuestList.from_string(
-            service.id, EMAIL_TYPE, "guest_list_user@digital.fake.gov"
+            service.id, GuestListRecipientType.EMAIL, "guest_list_user@digital.fake.gov"
         )
 
     db.session.add(guest_list_user)
diff --git a/tests/app/test_commands.py b/tests/app/test_commands.py
index c13ac3dd3..45d836105 100644
--- a/tests/app/test_commands.py
+++ b/tests/app/test_commands.py
@@ -23,10 +23,10 @@ from app.dao.users_dao import get_user_by_email
 from app.models import (
     KEY_TYPE_NORMAL,
     NOTIFICATION_DELIVERED,
-    SMS_TYPE,
     AnnualBilling,
     Job,
     Notification,
+    NotificationType,
     Organization,
     Service,
     Template,
@@ -314,7 +314,7 @@ def test_fix_billable_units(notify_db_session, notify_api, sample_template):
     create_notification(template=sample_template)
     notification = Notification.query.one()
     notification.billable_units = 0
-    notification.notification_type = SMS_TYPE
+    notification.notification_type = NotificationType.SMS
     notification.status = NOTIFICATION_DELIVERED
     notification.sent_at = None
     notification.key_type = KEY_TYPE_NORMAL
diff --git a/tests/app/test_model.py b/tests/app/test_model.py
index faab07182..f893ab14c 100644
--- a/tests/app/test_model.py
+++ b/tests/app/test_model.py
@@ -6,23 +6,22 @@ from sqlalchemy.exc import IntegrityError
 
 from app import encryption
 from app.models import (
-    EMAIL_TYPE,
-    MOBILE_TYPE,
     NOTIFICATION_CREATED,
     NOTIFICATION_FAILED,
     NOTIFICATION_PENDING,
     NOTIFICATION_STATUS_TYPES_FAILED,
     NOTIFICATION_TECHNICAL_FAILURE,
-    SMS_TYPE,
     Agreement,
     AgreementStatus,
     AgreementType,
     AnnualBilling,
+    GuestListRecipientType,
     Notification,
     NotificationHistory,
     Service,
     ServiceGuestList,
     ServicePermission,
+    TemplateType,
     User,
     VerifyCode,
     filter_null_value_fields,
@@ -43,7 +42,7 @@ from tests.app.db import (
 @pytest.mark.parametrize("mobile_number", ["+447700900855", "+12348675309"])
 def test_should_build_service_guest_list_from_mobile_number(mobile_number):
     service_guest_list = ServiceGuestList.from_string(
-        "service_id", MOBILE_TYPE, mobile_number
+        "service_id", GuestListRecipientType.MOBILE, mobile_number
     )
 
     assert service_guest_list.recipient == mobile_number
@@ -52,7 +51,7 @@ def test_should_build_service_guest_list_from_mobile_number(mobile_number):
 @pytest.mark.parametrize("email_address", ["test@example.com"])
 def test_should_build_service_guest_list_from_email_address(email_address):
     service_guest_list = ServiceGuestList.from_string(
-        "service_id", EMAIL_TYPE, email_address
+        "service_id", GuestListRecipientType.EMAIL, email_address
     )
 
     assert service_guest_list.recipient == email_address
@@ -60,7 +59,11 @@ def test_should_build_service_guest_list_from_email_address(email_address):
 
 @pytest.mark.parametrize(
     "contact, recipient_type",
-    [("", None), ("07700dsadsad", MOBILE_TYPE), ("gmail.com", EMAIL_TYPE)],
+    [
+        ("", None),
+        ("07700dsadsad", GuestListRecipientType.MOBILE),
+        ("gmail.com", GuestListRecipientType.EMAIL),
+    ],
 )
 def test_should_not_build_service_guest_list_from_invalid_contact(
     recipient_type, contact
@@ -201,7 +204,7 @@ def test_notification_personalisation_setter_always_sets_empty_dict(
 
 
 def test_notification_subject_is_none_for_sms(sample_service):
-    template = create_template(service=sample_service, template_type=SMS_TYPE)
+    template = create_template(service=sample_service, template_type=TemplateType.SMS)
     notification = create_notification(template=template)
     assert notification.subject is None