diff --git a/app/celery/scheduled_tasks.py b/app/celery/scheduled_tasks.py
index 3e58dfc02..52831ebc1 100644
--- a/app/celery/scheduled_tasks.py
+++ b/app/celery/scheduled_tasks.py
@@ -33,7 +33,10 @@ from app.dao.notifications_dao import (
     letters_missing_from_sending_bucket,
     is_delivery_slow_for_providers,
 )
-from app.dao.provider_details_dao import dao_reduce_sms_provider_priority
+from app.dao.provider_details_dao import (
+    dao_reduce_sms_provider_priority,
+    dao_adjust_provider_priority_back_to_resting_points
+)
 from app.dao.users_dao import delete_codes_older_created_more_than_a_day_ago
 from app.dao.services_dao import dao_find_services_sending_to_tv_numbers, dao_find_services_with_high_failure_rates
 from app.models import (
@@ -126,6 +129,12 @@ def switch_current_sms_provider_on_slow_delivery():
                 dao_reduce_sms_provider_priority(provider_name, time_threshold=timedelta(minutes=10))
 
 
+@notify_celery.task(name='tend-providers-back-to-middle')
+@statsd(namespace='tasks')
+def tend_providers_back_to_middle():
+    dao_adjust_provider_priority_back_to_resting_points()
+
+
 @notify_celery.task(name='check-job-status')
 @statsd(namespace="tasks")
 def check_job_status():
diff --git a/app/config.py b/app/config.py
index f248cf9ed..49136a50c 100644
--- a/app/config.py
+++ b/app/config.py
@@ -135,6 +135,12 @@ class Config(object):
 
     CHECK_PROXY_HEADER = False
 
+    # these should always add up to 100%
+    SMS_PROVIDER_RESTING_POINTS = {
+        'mmg': 60,
+        'firetext': 40
+    }
+
     NOTIFY_SERVICE_ID = 'd6aa2c68-a2d9-4437-ab19-3ae8eb202553'
     NOTIFY_USER_ID = '6af522d0-2915-4e52-83a3-3690455a5fe6'
     INVITATION_EMAIL_TEMPLATE_ID = '4f46df42-f795-4cc4-83bb-65ca312f49cc'
@@ -198,6 +204,11 @@ class Config(object):
             'schedule': crontab(),
             'options': {'queue': QueueNames.PERIODIC}
         },
+        'tend-providers-back-to-middle': {
+            'task': 'tend-providers-back-to-middle',
+            'schedule': crontab(minute='*/5'),
+            'options': {'queue': QueueNames.PERIODIC}
+        },
         'check-for-missing-rows-in-completed-jobs': {
             'task': 'check-for-missing-rows-in-completed-jobs',
             'schedule': crontab(minute='*/10'),
diff --git a/app/dao/provider_details_dao.py b/app/dao/provider_details_dao.py
index 1c4977bd8..d2da2efd4 100644
--- a/app/dao/provider_details_dao.py
+++ b/app/dao/provider_details_dao.py
@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from notifications_utils.timezones import convert_utc_to_bst
 from sqlalchemy import asc, desc, func
@@ -87,6 +87,47 @@ def dao_reduce_sms_provider_priority(identifier, *, time_threshold):
     _update_provider_details_without_commit(increased_provider)
 
 
+@transactional
+def dao_adjust_provider_priority_back_to_resting_points():
+    """
+    Provided that neither SMS provider has been modified in the last hour, move both providers by 10 percentage points
+    each towards their defined resting points (set in SMS_PROVIDER_RESTING_POINTS in config.py).
+    """
+    amount_to_reduce_by = 10
+    time_threshold = timedelta(hours=1)
+
+    # get current priority of both providers
+    providers = ProviderDetails.query.filter(
+        ProviderDetails.notification_type == 'sms',
+        ProviderDetails.active
+    ).with_for_update().all()
+
+    # if something updated recently, don't update again. If the updated_at is null, treat it as min time
+    if any((provider.updated_at or datetime.min) > datetime.utcnow() - time_threshold for provider in providers):
+        current_app.logger.info("Not adjusting providers, providers updated less than {} ago.".format(time_threshold))
+        return
+
+    # Automatic update so set as notify user
+    notify_user = get_user_by_id(current_app.config['NOTIFY_USER_ID'])
+    for provider in providers:
+        target = current_app.config['SMS_PROVIDER_RESTING_POINTS'][provider.identifier]
+        current = provider.priority
+
+        if current != target:
+            if current > target:
+                provider.priority = max(provider.priority - amount_to_reduce_by, target)
+            else:
+                provider.priority = min(provider.priority + amount_to_reduce_by, target)
+
+            provider.created_by_id = notify_user.id
+            _update_provider_details_without_commit(provider)
+            current_app.logger.info('Adjusting provider priority - {} going from {} to {}'.format(
+                provider.identifier,
+                current,
+                provider.priority,
+            ))
+
+
 def get_provider_details_by_notification_type(notification_type, supports_international=False):
 
     filters = [ProviderDetails.notification_type == notification_type]