diff --git a/app/celery/process_ses_receipts_tasks.py b/app/celery/process_ses_receipts_tasks.py
index 63a337ed5..6318d59c1 100644
--- a/app/celery/process_ses_receipts_tasks.py
+++ b/app/celery/process_ses_receipts_tasks.py
@@ -20,7 +20,7 @@ from app.dao.service_callback_api_dao import (
     get_service_complaint_callback_api_for_service,
     get_service_delivery_status_callback_api_for_service,
 )
-from app.enums import NotificationStatus
+from app.enums import CallbackType, NotificationStatus
 from app.models import Complaint
 
 
@@ -209,7 +209,7 @@ def handle_complaint(ses_message):
         )
         return
     notification = dao_get_notification_history_by_reference(reference)
-    ses_complaint = ses_message.get("complaint", None)
+    ses_complaint = ses_message.get(CallbackType.COMPLAINT, None)
 
     complaint = Complaint(
         notification_id=notification.id,
@@ -241,7 +241,7 @@ def remove_emails_from_bounce(bounce_dict):
 
 def remove_emails_from_complaint(complaint_dict):
     remove_mail_headers(complaint_dict)
-    complaint_dict["complaint"].pop("complainedRecipients")
+    complaint_dict[CallbackType.COMPLAINT].pop("complainedRecipients")
     return complaint_dict["mail"].pop("destination")
 
 
diff --git a/app/dao/annual_billing_dao.py b/app/dao/annual_billing_dao.py
index c5b05a437..0e4d3b96b 100644
--- a/app/dao/annual_billing_dao.py
+++ b/app/dao/annual_billing_dao.py
@@ -3,6 +3,7 @@ from flask import current_app
 from app import db
 from app.dao.dao_utils import autocommit
 from app.dao.date_util import get_current_calendar_year_start_year
+from app.enums import OrganizationType
 from app.models import AnnualBilling
 
 
@@ -65,17 +66,17 @@ def dao_get_all_free_sms_fragment_limit(service_id):
 
 def set_default_free_allowance_for_service(service, year_start=None):
     default_free_sms_fragment_limits = {
-        "federal": {
+        OrganizationType.FEDERAL: {
             2020: 250_000,
             2021: 150_000,
             2022: 40_000,
         },
-        "state": {
+        OrganizationType.STATE: {
             2020: 250_000,
             2021: 150_000,
             2022: 40_000,
         },
-        "other": {
+        OrganizationType.OTHER: {
             2020: 250_000,
             2021: 150_000,
             2022: 40_000,
@@ -97,7 +98,9 @@ def set_default_free_allowance_for_service(service, year_start=None):
             f"no organization type for service {service.id}. Using other default of "
             f"{default_free_sms_fragment_limits['other'][year_start]}"
         )
-        free_allowance = default_free_sms_fragment_limits["other"][year_start]
+        free_allowance = default_free_sms_fragment_limits[OrganizationType.OTHER][
+            year_start
+        ]
 
     return dao_create_or_update_annual_billing_for_year(
         service.id, free_allowance, year_start
diff --git a/tests/app/celery/test_process_ses_receipts_tasks.py b/tests/app/celery/test_process_ses_receipts_tasks.py
index 7edfc91ac..0b9a45b23 100644
--- a/tests/app/celery/test_process_ses_receipts_tasks.py
+++ b/tests/app/celery/test_process_ses_receipts_tasks.py
@@ -16,7 +16,7 @@ from app.celery.test_key_tasks import (
     ses_soft_bounce_callback,
 )
 from app.dao.notifications_dao import get_notification_by_id
-from app.enums import NotificationStatus
+from app.enums import CallbackType, NotificationStatus
 from app.models import Complaint
 from tests.app.conftest import create_sample_notification
 from tests.app.db import (
@@ -407,7 +407,7 @@ def test_ses_callback_should_send_on_complaint_to_user_callback_api(
     create_service_callback_api(
         service=sample_email_template.service,
         url="https://original_url.com",
-        callback_type="complaint",
+        callback_type=CallbackType.COMPLAINT,
     )
     notification = create_notification(
         template=sample_email_template,
diff --git a/tests/app/celery/test_service_callback_tasks.py b/tests/app/celery/test_service_callback_tasks.py
index 2e050e9f8..163893d41 100644
--- a/tests/app/celery/test_service_callback_tasks.py
+++ b/tests/app/celery/test_service_callback_tasks.py
@@ -27,7 +27,10 @@ from tests.app.db import (
 def test_send_delivery_status_to_service_post_https_request_to_service_with_encrypted_data(
     notify_db_session, notification_type
 ):
-    callback_api, template = _set_up_test_data(notification_type, "delivery_status")
+    callback_api, template = _set_up_test_data(
+        notification_type,
+        CallbackType.DELIVERY_STATUS,
+    )
     datestr = datetime(2017, 6, 20)
 
     notification = create_notification(
diff --git a/tests/app/dao/test_annual_billing_dao.py b/tests/app/dao/test_annual_billing_dao.py
index 182d94efc..f4c3e3d57 100644
--- a/tests/app/dao/test_annual_billing_dao.py
+++ b/tests/app/dao/test_annual_billing_dao.py
@@ -67,17 +67,17 @@ def test_dao_update_annual_billing_for_future_years(notify_db_session, sample_se
 @pytest.mark.parametrize(
     "org_type, year, expected_default",
     [
-        ("federal", 2021, 150000),
-        ("state", 2021, 150000),
+        (OrganizationType.FEDERAL, 2021, 150000),
+        (OrganizationType.STATE, 2021, 150000),
         (None, 2021, 150000),
-        ("federal", 2020, 250000),
-        ("state", 2020, 250000),
-        ("other", 2020, 250000),
+        (OrganizationType.FEDERAL, 2020, 250000),
+        (OrganizationType.STATE, 2020, 250000),
+        (OrganizationType.OTHER, 2020, 250000),
         (None, 2020, 250000),
-        ("federal", 2019, 250000),
-        ("federal", 2022, 40000),
-        ("state", 2022, 40000),
-        ("federal", 2023, 40000),
+        (OrganizationType.FEDERAL, 2019, 250000),
+        (OrganizationType.FEDERAL, 2022, 40000),
+        (OrganizationType.STATE, 2022, 40000),
+        (OrganizationType.FEDERAL, 2023, 40000),
     ],
 )
 def test_set_default_free_allowance_for_service(
diff --git a/tests/app/dao/test_service_callback_api_dao.py b/tests/app/dao/test_service_callback_api_dao.py
index ab17dbb23..eb7ac0548 100644
--- a/tests/app/dao/test_service_callback_api_dao.py
+++ b/tests/app/dao/test_service_callback_api_dao.py
@@ -10,6 +10,7 @@ from app.dao.service_callback_api_dao import (
     reset_service_callback_api,
     save_service_callback_api,
 )
+from app.enums import CallbackType
 from app.models import ServiceCallbackApi
 from tests.app.db import create_service_callback_api
 
@@ -65,7 +66,7 @@ def test_update_service_callback_api_unique_constraint(sample_service):
         url="https://some_service/callback_endpoint",
         bearer_token="some_unique_string",
         updated_by_id=sample_service.users[0].id,
-        callback_type="delivery_status",
+        callback_type=CallbackType.DELIVERY_STATUS,
     )
     save_service_callback_api(service_callback_api)
     another = ServiceCallbackApi(
@@ -73,7 +74,7 @@ def test_update_service_callback_api_unique_constraint(sample_service):
         url="https://some_service/another_callback_endpoint",
         bearer_token="different_string",
         updated_by_id=sample_service.users[0].id,
-        callback_type="delivery_status",
+        callback_type=CallbackType.DELIVERY_STATUS,
     )
     with pytest.raises(expected_exception=SQLAlchemyError):
         save_service_callback_api(another)
@@ -85,7 +86,7 @@ def test_update_service_callback_can_add_two_api_of_different_types(sample_servi
         url="https://some_service/callback_endpoint",
         bearer_token="some_unique_string",
         updated_by_id=sample_service.users[0].id,
-        callback_type="delivery_status",
+        callback_type=CallbackType.DELIVERY_STATUS,
     )
     save_service_callback_api(delivery_status)
     complaint = ServiceCallbackApi(
@@ -93,7 +94,7 @@ def test_update_service_callback_can_add_two_api_of_different_types(sample_servi
         url="https://some_service/another_callback_endpoint",
         bearer_token="different_string",
         updated_by_id=sample_service.users[0].id,
-        callback_type="complaint",
+        callback_type=CallbackType.COMPLAINT,
     )
     save_service_callback_api(complaint)
     results = ServiceCallbackApi.query.order_by(ServiceCallbackApi.callback_type).all()
diff --git a/tests/app/db.py b/tests/app/db.py
index 632c3a8a6..07f138c41 100644
--- a/tests/app/db.py
+++ b/tests/app/db.py
@@ -27,6 +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.enums import (
+    CallbackType,
     JobStatus,
     KeyType,
     NotificationStatus,
@@ -482,7 +483,7 @@ def create_service_callback_api(
     service,
     url="https://something.com",
     bearer_token="some_super_secret",
-    callback_type="delivery_status",
+    callback_type=CallbackType.DELIVERY_STATUS,
 ):
     service_callback_api = ServiceCallbackApi(
         service_id=service.id,
diff --git a/tests/app/job/test_rest.py b/tests/app/job/test_rest.py
index acf453c37..289cf0c7f 100644
--- a/tests/app/job/test_rest.py
+++ b/tests/app/job/test_rest.py
@@ -28,7 +28,7 @@ from tests.conftest import set_config
 
 
 def test_get_job_with_invalid_service_id_returns404(client, sample_service):
-    path = "/service/{}/job".format(sample_service.id)
+    path = f"/service/{sample_service.id}/job"
     auth_header = create_admin_authorization_header()
     response = client.get(path, headers=[auth_header])
     assert response.status_code == 200
@@ -38,7 +38,7 @@ def test_get_job_with_invalid_service_id_returns404(client, sample_service):
 
 def test_get_job_with_invalid_job_id_returns404(client, sample_template):
     service_id = sample_template.service.id
-    path = "/service/{}/job/{}".format(service_id, "bad-id")
+    path = f"/service/{service_id}/job/{'bad-id'}"
     auth_header = create_admin_authorization_header()
     response = client.get(path, headers=[auth_header])
     assert response.status_code == 404
@@ -49,7 +49,7 @@ def test_get_job_with_invalid_job_id_returns404(client, sample_template):
 
 def test_get_job_with_unknown_id_returns404(client, sample_template, fake_uuid):
     service_id = sample_template.service.id
-    path = "/service/{}/job/{}".format(service_id, fake_uuid)
+    path = f"/service/{service_id}/job/{fake_uuid}"
     auth_header = create_admin_authorization_header()
     response = client.get(path, headers=[auth_header])
     assert response.status_code == 404
@@ -60,7 +60,7 @@ def test_get_job_with_unknown_id_returns404(client, sample_template, fake_uuid):
 def test_cancel_job(client, sample_scheduled_job):
     job_id = str(sample_scheduled_job.id)
     service_id = sample_scheduled_job.service.id
-    path = "/service/{}/job/{}/cancel".format(service_id, job_id)
+    path = f"/service/{service_id}/job/{job_id}/cancel"
     auth_header = create_admin_authorization_header()
     response = client.post(path, headers=[auth_header])
     assert response.status_code == 200
@@ -73,7 +73,7 @@ def test_cant_cancel_normal_job(client, sample_job, mocker):
     job_id = str(sample_job.id)
     service_id = sample_job.service.id
     mock_update = mocker.patch("app.dao.jobs_dao.dao_update_job")
-    path = "/service/{}/job/{}/cancel".format(service_id, job_id)
+    path = f"/service/{service_id}/job/{job_id}/cancel"
     auth_header = create_admin_authorization_header()
     response = client.post(path, headers=[auth_header])
     assert response.status_code == 404
@@ -95,7 +95,7 @@ def test_create_unscheduled_job(client, sample_template, mocker, fake_uuid):
         "id": fake_uuid,
         "created_by": str(sample_template.created_by.id),
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
 
@@ -136,7 +136,7 @@ def test_create_unscheduled_job_with_sender_id_in_metadata(
         "id": fake_uuid,
         "created_by": str(sample_template.created_by.id),
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
 
@@ -168,7 +168,7 @@ def test_create_scheduled_job(client, sample_template, mocker, fake_uuid):
         "created_by": str(sample_template.created_by.id),
         "scheduled_for": scheduled_date,
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
 
@@ -197,7 +197,7 @@ def test_create_job_returns_403_if_service_is_not_active(
     mock_job_dao = mocker.patch("app.dao.jobs_dao.dao_create_job")
     auth_header = create_admin_authorization_header()
     response = client.post(
-        "/service/{}/job".format(sample_service.id),
+        f"/service/{sample_service.id}/job",
         data="",
         headers=[("Content-Type", "application/json"), auth_header],
     )
@@ -229,12 +229,12 @@ def test_create_job_returns_400_if_file_is_invalid(
         template_id=str(sample_template.id),
         original_file_name="thisisatest.csv",
         notification_count=1,
-        **extra_metadata
+        **extra_metadata,
     )
     mocker.patch("app.job.rest.get_job_metadata_from_s3", return_value=metadata)
     data = {"id": fake_uuid}
     response = client.post(
-        "/service/{}/job".format(sample_template.service.id),
+        f"/service/{sample_template.service.id}/job",
         data=json.dumps(data),
         headers=[("Content-Type", "application/json"), auth_header],
     )
@@ -266,7 +266,7 @@ def test_should_not_create_scheduled_job_more_then_96_hours_in_the_future(
         "created_by": str(sample_template.created_by.id),
         "scheduled_for": scheduled_date,
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
 
@@ -303,7 +303,7 @@ def test_should_not_create_scheduled_job_in_the_past(
         "created_by": str(sample_template.created_by.id),
         "scheduled_for": scheduled_date,
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
 
@@ -327,7 +327,7 @@ def test_create_job_returns_400_if_missing_id(client, sample_template, mocker):
         },
     )
     data = {}
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
     response = client.post(path, data=json.dumps(data), headers=headers)
@@ -354,7 +354,7 @@ def test_create_job_returns_400_if_missing_data(
         "id": fake_uuid,
         "valid": "True",
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
     response = client.post(path, data=json.dumps(data), headers=headers)
@@ -385,7 +385,7 @@ def test_create_job_returns_404_if_template_does_not_exist(
     data = {
         "id": fake_uuid,
     }
-    path = "/service/{}/job".format(sample_service.id)
+    path = f"/service/{sample_service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
     response = client.post(path, data=json.dumps(data), headers=headers)
@@ -408,7 +408,7 @@ def test_create_job_returns_404_if_missing_service(client, sample_template, mock
     )
     random_id = str(uuid.uuid4())
     data = {}
-    path = "/service/{}/job".format(random_id)
+    path = f"/service/{random_id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
     response = client.post(path, data=json.dumps(data), headers=headers)
@@ -437,7 +437,7 @@ def test_create_job_returns_400_if_archived_template(
         "id": fake_uuid,
         "valid": "True",
     }
-    path = "/service/{}/job".format(sample_template.service.id)
+    path = f"/service/{sample_template.service.id}/job"
     auth_header = create_admin_authorization_header()
     headers = [("Content-Type", "application/json"), auth_header]
     response = client.post(path, data=json.dumps(data), headers=headers)
diff --git a/tests/app/organization/test_invite_rest.py b/tests/app/organization/test_invite_rest.py
index fc5cf045d..c57fa8dd0 100644
--- a/tests/app/organization/test_invite_rest.py
+++ b/tests/app/organization/test_invite_rest.py
@@ -158,7 +158,7 @@ def test_get_invited_user_by_organization_when_user_does_not_belong_to_the_org(
 def test_update_org_invited_user_set_status_to_cancelled(
     admin_request, sample_invited_org_user
 ):
-    data = {"status": "cancelled"}
+    data = {"status": InvitedUserStatus.CANCELLED}
 
     json_resp = admin_request.post(
         "organization_invite.update_org_invite_status",
@@ -166,13 +166,13 @@ def test_update_org_invited_user_set_status_to_cancelled(
         invited_org_user_id=sample_invited_org_user.id,
         _data=data,
     )
-    assert json_resp["data"]["status"] == "cancelled"
+    assert json_resp["data"]["status"] == InvitedUserStatus.CANCELLED
 
 
 def test_update_org_invited_user_for_wrong_service_returns_404(
     admin_request, sample_invited_org_user, fake_uuid
 ):
-    data = {"status": "cancelled"}
+    data = {"status": InvitedUserStatus.CANCELLED}
 
     json_resp = admin_request.post(
         "organization_invite.update_org_invite_status",
diff --git a/tests/app/organization/test_rest.py b/tests/app/organization/test_rest.py
index 74bf7ac71..914dca008 100644
--- a/tests/app/organization/test_rest.py
+++ b/tests/app/organization/test_rest.py
@@ -580,7 +580,7 @@ def test_post_link_service_to_organization(admin_request, sample_service):
         _expected_status=204,
     )
     assert len(organization.services) == 1
-    assert sample_service.organization_type == "federal"
+    assert sample_service.organization_type == OrganizationType.FEDERAL
 
 
 @freeze_time("2021-09-24 13:30")
diff --git a/tests/app/service/send_notification/test_send_notification.py b/tests/app/service/send_notification/test_send_notification.py
index 6b5441efb..d85cb939a 100644
--- a/tests/app/service/send_notification/test_send_notification.py
+++ b/tests/app/service/send_notification/test_send_notification.py
@@ -12,7 +12,7 @@ from app.dao import notifications_dao
 from app.dao.api_key_dao import save_model_api_key
 from app.dao.services_dao import dao_update_service
 from app.dao.templates_dao import dao_get_all_templates_for_service, dao_update_template
-from app.enums import KeyType, NotificationType, TemplateType
+from app.enums import KeyType, NotificationType, TemplateProcessType, TemplateType
 from app.errors import InvalidRequest
 from app.models import ApiKey, Notification, NotificationHistory, Template
 from app.service.send_notification import send_one_off_notification
@@ -1132,7 +1132,9 @@ def test_send_notification_uses_priority_queue_when_template_is_marked_as_priori
     send_to,
 ):
     sample = create_template(
-        sample_service, template_type=notification_type, process_type="priority"
+        sample_service,
+        template_type=notification_type,
+        process_type=TemplateProcessType.PRIORITY,
     )
     mocked = mocker.patch(
         f"app.celery.provider_tasks.deliver_{notification_type}.apply_async"
diff --git a/tests/app/service_invite/test_service_invite_rest.py b/tests/app/service_invite/test_service_invite_rest.py
index 482ec1944..00574ca3f 100644
--- a/tests/app/service_invite/test_service_invite_rest.py
+++ b/tests/app/service_invite/test_service_invite_rest.py
@@ -229,7 +229,7 @@ def test_resend_expired_invite(
 
 
 def test_update_invited_user_set_status_to_cancelled(client, sample_invited_user):
-    data = {"status": "cancelled"}
+    data = {"status": InvitedUserStatus.CANCELLED}
     url = f"/service/{sample_invited_user.service_id}/invite/{sample_invited_user.id}"
     auth_header = create_admin_authorization_header()
     response = client.post(
@@ -246,7 +246,7 @@ def test_update_invited_user_set_status_to_cancelled(client, sample_invited_user
 def test_update_invited_user_for_wrong_service_returns_404(
     client, sample_invited_user, fake_uuid
 ):
-    data = {"status": "cancelled"}
+    data = {"status": InvitedUserStatus.CANCELLED}
     url = f"/service/{fake_uuid}/invite/{sample_invited_user.id}"
     auth_header = create_admin_authorization_header()
     response = client.post(
diff --git a/tests/app/template/test_rest.py b/tests/app/template/test_rest.py
index fb6fdcf74..93b36939f 100644
--- a/tests/app/template/test_rest.py
+++ b/tests/app/template/test_rest.py
@@ -798,7 +798,7 @@ def test_update_does_not_create_new_version_when_there_is_no_change(
 
 def test_update_set_process_type_on_template(client, sample_template):
     auth_header = create_admin_authorization_header()
-    data = {"process_type": "priority"}
+    data = {"process_type": TemplateProcessType.PRIORITY}
     resp = client.post(
         f"/service/{sample_template.service_id}/template/{sample_template.id}",
         data=json.dumps(data),
@@ -807,7 +807,7 @@ def test_update_set_process_type_on_template(client, sample_template):
     assert resp.status_code == 200
 
     template = dao_get_template_by_id(sample_template.id)
-    assert template.process_type == "priority"
+    assert template.process_type == TemplateProcessType.PRIORITY
 
 
 @pytest.mark.parametrize(
diff --git a/tests/app/template/test_rest_history.py b/tests/app/template/test_rest_history.py
index ee902d381..6aa234de0 100644
--- a/tests/app/template/test_rest_history.py
+++ b/tests/app/template/test_rest_history.py
@@ -39,7 +39,7 @@ def test_template_history_version(notify_api, sample_user, sample_template):
 def test_previous_template_history_version(notify_api, sample_template):
     old_content = sample_template.content
     sample_template.content = "New content"
-    sample_template.process_type = "priority"
+    sample_template.process_type = TemplateProcessType.PRIORITY
     dao_update_template(sample_template)
     with notify_api.test_request_context():
         with notify_api.test_client() as client:
diff --git a/tests/app/v2/notifications/test_post_notifications.py b/tests/app/v2/notifications/test_post_notifications.py
index 12359a477..5a1888a93 100644
--- a/tests/app/v2/notifications/test_post_notifications.py
+++ b/tests/app/v2/notifications/test_post_notifications.py
@@ -13,6 +13,7 @@ from app.enums import (
     NotificationStatus,
     NotificationType,
     ServicePermissionType,
+    TemplateProcessType,
     TemplateType,
 )
 from app.models import Notification
@@ -580,7 +581,9 @@ def test_send_notification_uses_priority_queue_when_template_is_marked_as_priori
     mocker.patch(f"app.celery.provider_tasks.deliver_{notification_type}.apply_async")
 
     sample = create_template(
-        service=sample_service, template_type=notification_type, process_type="priority"
+        service=sample_service,
+        template_type=notification_type,
+        process_type=TemplateProcessType.PRIORITY,
     )
     mocked = mocker.patch(
         f"app.celery.provider_tasks.deliver_{notification_type}.apply_async"