diff --git a/app/accept_invite/rest.py b/app/accept_invite/rest.py
index a914654e9..1a0366f5e 100644
--- a/app/accept_invite/rest.py
+++ b/app/accept_invite/rest.py
@@ -10,7 +10,11 @@ from notifications_utils.url_safe_token import check_token
 
 from app.dao.invited_user_dao import get_invited_user_by_id
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
+
 from app.schemas import invited_user_schema
 
 
@@ -30,7 +34,8 @@ def get_invited_user_by_token(token):
                                       max_age_seconds)
     except SignatureExpired:
         message = 'Invitation with id {} expired'.format(invited_user_id)
-        return jsonify(result='error', message=message), 400
+        errors = {'invitation': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
     invited_user = get_invited_user_by_id(invited_user_id)
 
diff --git a/app/errors.py b/app/errors.py
index c3cc70c01..9d90dee15 100644
--- a/app/errors.py
+++ b/app/errors.py
@@ -4,9 +4,10 @@ from flask import (
 )
 from sqlalchemy.exc import SQLAlchemyError, DataError
 from sqlalchemy.orm.exc import NoResultFound
+from marshmallow import ValidationError
 
 
-class InvalidData(Exception):
+class InvalidRequest(Exception):
 
     def __init__(self, message, status_code):
         super().__init__()
@@ -22,7 +23,12 @@ class InvalidData(Exception):
 
 def register_errors(blueprint):
 
-    @blueprint.app_errorhandler(InvalidData)
+    @blueprint.app_errorhandler(ValidationError)
+    def validation_error(error):
+        current_app.logger.error(error)
+        return jsonify(result='error', message=error.messages), 400
+
+    @blueprint.app_errorhandler(InvalidRequest)
     def invalid_data(error):
         response = jsonify(error.to_dict())
         response.status_code = error.status_code
diff --git a/app/events/rest.py b/app/events/rest.py
index d3d38454e..6bd189617 100644
--- a/app/events/rest.py
+++ b/app/events/rest.py
@@ -5,6 +5,7 @@ from flask import (
 )
 
 from app.errors import register_errors
+
 from app.schemas import event_schema
 from app.dao.events_dao import dao_create_event
 
@@ -15,8 +16,6 @@ register_errors(events)
 @events.route('', methods=['POST'])
 def create_event():
     data = request.get_json()
-    event, errors = event_schema.load(data)
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    event = event_schema.load(data).data
     dao_create_event(event)
     return jsonify(data=event_schema.dump(event).data), 201
diff --git a/app/invite/rest.py b/app/invite/rest.py
index 14a6dae84..9190ad252 100644
--- a/app/invite/rest.py
+++ b/app/invite/rest.py
@@ -19,14 +19,13 @@ from app.celery.tasks import (email_invited_user)
 invite = Blueprint('invite', __name__, url_prefix='/service/<service_id>/invite')
 
 from app.errors import register_errors
+
 register_errors(invite)
 
 
 @invite.route('', methods=['POST'])
 def create_invited_user(service_id):
     invited_user, errors = invited_user_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
     save_invited_user(invited_user)
     invitation = _create_invitation(invited_user)
     encrypted_invitation = encryption.encrypt(invitation)
@@ -53,9 +52,7 @@ def update_invited_user(service_id, invited_user_id):
 
     current_data = dict(invited_user_schema.dump(fetched).data.items())
     current_data.update(request.get_json())
-    update_dict, errors = invited_user_schema.load(current_data)
-    if errors:
-        return jsonify(result='error', message=errors), 400
+    update_dict = invited_user_schema.load(current_data).data
     save_invited_user(update_dict)
     return jsonify(data=invited_user_schema.dump(fetched).data), 200
 
diff --git a/app/job/rest.py b/app/job/rest.py
index 9b2d44382..fc3d49943 100644
--- a/app/job/rest.py
+++ b/app/job/rest.py
@@ -1,8 +1,8 @@
 from flask import (
     Blueprint,
     jsonify,
-    request,
-    current_app)
+    request
+)
 
 from app.dao.jobs_dao import (
     dao_create_job,
@@ -22,7 +22,10 @@ from app.celery.tasks import process_job
 
 job = Blueprint('job', __name__, url_prefix='/service/<uuid:service_id>/job')
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 register_errors(job)
 
@@ -30,7 +33,7 @@ register_errors(job)
 @job.route('/<job_id>', methods=['GET'])
 def get_job_by_service_and_job_id(service_id, job_id):
     job = dao_get_job_by_service_id_and_job_id(service_id, job_id)
-    data, errors = job_schema.dump(job)
+    data = job_schema.dump(job).data
     return jsonify(data=data)
 
 
@@ -40,16 +43,13 @@ def get_jobs_by_service(service_id):
         try:
             limit_days = int(request.args['limit_days'])
         except ValueError as e:
-            error = '{} is not an integer'.format(request.args['limit_days'])
-            current_app.logger.error(error)
-            return jsonify(result="error", message={'limit_days': [error]}), 400
+            errors = {'limit_days': ['{} is not an integer'.format(request.args['limit_days'])]}
+            raise InvalidRequest(errors, status_code=400)
     else:
         limit_days = None
 
     jobs = dao_get_jobs_by_service_id(service_id, limit_days)
-    data, errors = job_schema.dump(jobs, many=True)
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    data = job_schema.dump(jobs, many=True).data
     return jsonify(data=data)
 
 
@@ -66,13 +66,10 @@ def create_job(service_id):
     errors = unarchived_template_schema.validate({'archived': template.archived})
 
     if errors:
-        return jsonify(result='error', message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
 
     data.update({"template_version": template.version})
-    job, errors = job_schema.load(data)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    job = job_schema.load(data).data
     dao_create_job(job)
     process_job.apply_async([str(job.id)], queue="process-job")
     return jsonify(data=job_schema.dump(job).data), 201
diff --git a/app/notifications/rest.py b/app/notifications/rest.py
index 7f4029a65..ab5cf2168 100644
--- a/app/notifications/rest.py
+++ b/app/notifications/rest.py
@@ -35,7 +35,10 @@ from app.celery.tasks import send_sms, send_email
 
 notifications = Blueprint('notifications', __name__)
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 register_errors(notifications)
 
@@ -47,16 +50,12 @@ def process_ses_response():
         ses_request = json.loads(request.data)
         errors = validate_callback_data(data=ses_request, fields=['Message'], client_name=client_name)
         if errors:
-            return jsonify(
-                result="error", message=errors
-            ), 400
+            raise InvalidRequest(errors, status_code=400)
 
         ses_message = json.loads(ses_request['Message'])
         errors = validate_callback_data(data=ses_message, fields=['notificationType'], client_name=client_name)
         if errors:
-            return jsonify(
-                result="error", message=errors
-            ), 400
+            raise InvalidRequest(errors, status_code=400)
 
         notification_type = ses_message['notificationType']
         if notification_type == 'Bounce':
@@ -67,12 +66,8 @@ def process_ses_response():
         try:
             aws_response_dict = get_aws_responses(notification_type)
         except KeyError:
-            message = "{} callback failed: status {} not found".format(client_name, notification_type)
-            current_app.logger.info(message)
-            return jsonify(
-                result="error",
-                message=message
-            ), 400
+            error = "{} callback failed: status {} not found".format(client_name, notification_type)
+            raise InvalidRequest(error, status_code=400)
 
         notification_status = aws_response_dict['notification_status']
         notification_statistics_status = aws_response_dict['notification_statistics_status']
@@ -93,15 +88,9 @@ def process_ses_response():
                     notification_status,
                     notification_statistics_status
             ):
-                message = "SES callback failed: notification either not found or already updated " \
-                          "from sending. Status {}".format(notification_status)
-                current_app.logger.info(
-                    message
-                )
-                return jsonify(
-                    result="error",
-                    message=message
-                ), 404
+                error = "SES callback failed: notification either not found or already updated " \
+                        "from sending. Status {}".format(notification_status)
+                raise InvalidRequest(error, status_code=404)
 
             if not aws_response_dict['success']:
                 current_app.logger.info(
@@ -117,20 +106,12 @@ def process_ses_response():
             ), 200
 
         except KeyError:
-            current_app.logger.error(
-                "SES callback failed: messageId missing"
-            )
-            return jsonify(
-                result="error", message="SES callback failed: messageId missing"
-            ), 400
+            message = "SES callback failed: messageId missing"
+            raise InvalidRequest(message, status_code=400)
 
     except ValueError as ex:
-        current_app.logger.exception(
-            "{} callback failed: invalid json {}".format(client_name, ex)
-        )
-        return jsonify(
-            result="error", message="{} callback failed: invalid json".format(client_name)
-        ), 400
+        error = "{} callback failed: invalid json".format(client_name)
+        raise InvalidRequest(error, status_code=400)
 
 
 def is_not_a_notification(source):
@@ -149,19 +130,17 @@ def is_not_a_notification(source):
 def process_mmg_response():
     client_name = 'MMG'
     data = json.loads(request.data)
-    validation_errors = validate_callback_data(data=data,
-                                               fields=['status', 'CID'],
-                                               client_name=client_name)
-    if validation_errors:
-        [current_app.logger.info(e) for e in validation_errors]
-        return jsonify(result='error', message=validation_errors), 400
+    errors = validate_callback_data(data=data,
+                                    fields=['status', 'CID'],
+                                    client_name=client_name)
+    if errors:
+        raise InvalidRequest(errors, status_code=400)
 
     success, errors = process_sms_client_response(status=str(data.get('status')),
                                                   reference=data.get('CID'),
                                                   client_name=client_name)
     if errors:
-        [current_app.logger.info(e) for e in errors]
-        return jsonify(result='error', message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
     else:
         return jsonify(result='success', message=success), 200
 
@@ -169,12 +148,11 @@ def process_mmg_response():
 @notifications.route('/notifications/sms/firetext', methods=['POST'])
 def process_firetext_response():
     client_name = 'Firetext'
-    validation_errors = validate_callback_data(data=request.form,
-                                               fields=['status', 'reference'],
-                                               client_name=client_name)
-    if validation_errors:
-        current_app.logger.info(validation_errors)
-        return jsonify(result='error', message=validation_errors), 400
+    errors = validate_callback_data(data=request.form,
+                                    fields=['status', 'reference'],
+                                    client_name=client_name)
+    if errors:
+        raise InvalidRequest(errors, status_code=400)
 
     response_code = request.form.get('code')
     status = request.form.get('status')
@@ -185,8 +163,7 @@ def process_firetext_response():
                                                   reference=request.form.get('reference'),
                                                   client_name=client_name)
     if errors:
-        [current_app.logger.info(e) for e in errors]
-        return jsonify(result='error', message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
     else:
         return jsonify(result='success', message=success), 200
 
@@ -199,10 +176,7 @@ def get_notifications(notification_id):
 
 @notifications.route('/notifications', methods=['GET'])
 def get_all_notifications():
-    data, errors = notifications_filter_schema.load(request.args)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    data = notifications_filter_schema.load(request.args).data
     page = data['page'] if 'page' in data else 1
     page_size = data['page_size'] if 'page_size' in data else current_app.config.get('PAGE_SIZE')
     limit_days = data.get('limit_days')
@@ -228,10 +202,7 @@ def get_all_notifications():
 @notifications.route('/service/<service_id>/notifications', methods=['GET'])
 @require_admin()
 def get_all_notifications_for_service(service_id):
-    data, errors = notifications_filter_schema.load(request.args)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    data = notifications_filter_schema.load(request.args).data
     page = data['page'] if 'page' in data else 1
     page_size = data['page_size'] if 'page_size' in data else current_app.config.get('PAGE_SIZE')
     limit_days = data.get('limit_days')
@@ -259,10 +230,7 @@ def get_all_notifications_for_service(service_id):
 @notifications.route('/service/<service_id>/job/<job_id>/notifications', methods=['GET'])
 @require_admin()
 def get_all_notifications_for_service_job(service_id, job_id):
-    data, errors = notifications_filter_schema.load(request.args)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    data = notifications_filter_schema.load(request.args).data
     page = data['page'] if 'page' in data else 1
     page_size = data['page_size'] if 'page_size' in data else current_app.config.get('PAGE_SIZE')
 
@@ -317,15 +285,15 @@ def send_notification(notification_type):
         total_email_count = service_stats.emails_requested
 
         if (total_email_count + total_sms_count >= service.message_limit) and service.restricted:
-            return jsonify(result="error", message='Exceeded send limits ({}) for today'.format(
-                service.message_limit)), 429
+            error = 'Exceeded send limits ({}) for today'.format(service.message_limit)
+            raise InvalidRequest(error, status_code=429)
 
     notification, errors = (
         sms_template_notification_schema if notification_type == 'sms' else email_notification_schema
     ).load(request.get_json())
 
     if errors:
-        return jsonify(result="error", message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
 
     template = templates_dao.dao_get_template_by_id_and_service_id(
         template_id=notification['template'],
@@ -334,33 +302,24 @@ def send_notification(notification_type):
 
     errors = unarchived_template_schema.validate({'archived': template.archived})
     if errors:
-        return jsonify(result='error', message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
 
     template_object = Template(template.__dict__, notification.get('personalisation', {}))
     if template_object.missing_data:
-        return jsonify(
-            result="error",
-            message={
-                'template': ['Missing personalisation: {}'.format(
-                    ", ".join(template_object.missing_data)
-                )]
-            }
-        ), 400
+        message = 'Missing personalisation: {}'.format(", ".join(template_object.missing_data))
+        errors = {'template': [message]}
+        raise InvalidRequest(errors, status_code=400)
+
     if template_object.additional_data:
-        return jsonify(
-            result="error",
-            message={
-                'template': ['Personalisation not needed for template: {}'.format(
-                    ", ".join(template_object.additional_data)
-                )]
-            }
-        ), 400
+        message = 'Personalisation not needed for template: {}'.format(", ".join(template_object.additional_data))
+        errors = {'template': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
     if template_object.replaced_content_count > current_app.config.get('SMS_CHAR_COUNT_LIMIT'):
-        return jsonify(
-            result="error",
-            message={'content': ['Content has a character count greater than the limit of {}'.format(
-                current_app.config.get('SMS_CHAR_COUNT_LIMIT'))]}), 400
+        char_count = current_app.config.get('SMS_CHAR_COUNT_LIMIT')
+        message = 'Content has a character count greater than the limit of {}'.format(char_count)
+        errors = {'content': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
     if service.restricted and not allowed_to_send_to(
         notification['to'],
@@ -368,11 +327,9 @@ def send_notification(notification_type):
             [user.mobile_number, user.email_address] for user in service.users
         )
     ):
-        return jsonify(
-            result="error", message={
-                'to': ['Invalid {} for restricted service'.format(first_column_heading[notification_type])]
-            }
-        ), 400
+        message = 'Invalid {} for restricted service'.format(first_column_heading[notification_type])
+        errors = {'to': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
     notification_id = create_uuid()
     notification.update({"template_version": template.version})
@@ -397,13 +354,9 @@ def send_notification(notification_type):
 
 @notifications.route('/notifications/statistics')
 def get_notification_statistics_for_day():
-    data, errors = day_schema.load(request.args)
-    if errors:
-        return jsonify(result='error', message=errors), 400
-
+    data = day_schema.load(request.args).data
     statistics = notifications_dao.dao_get_potential_notification_statistics_for_day(
         day=data['day']
     )
-
     data, errors = notifications_statistics_schema.dump(statistics, many=True)
     return jsonify(data=data), 200
diff --git a/app/notifications_statistics/rest.py b/app/notifications_statistics/rest.py
index f864e473b..69b1eafab 100644
--- a/app/notifications_statistics/rest.py
+++ b/app/notifications_statistics/rest.py
@@ -19,7 +19,10 @@ notifications_statistics = Blueprint(
     __name__, url_prefix='/service/<service_id>/notifications-statistics'
 )
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 register_errors(notifications_statistics)
 
@@ -34,9 +37,9 @@ def get_all_notification_statistics_for_service(service_id):
                 limit_days=int(request.args['limit_days'])
             )
         except ValueError as e:
-            error = '{} is not an integer'.format(request.args['limit_days'])
-            current_app.logger.error(error)
-            return jsonify(result="error", message={'limit_days': [error]}), 400
+            message = '{} is not an integer'.format(request.args['limit_days'])
+            errors = {'limit_days': [message]}
+            raise InvalidRequest(errors, status_code=400)
     else:
         statistics = dao_get_notification_statistics_for_service(service_id=service_id)
 
@@ -46,9 +49,7 @@ def get_all_notification_statistics_for_service(service_id):
 
 @notifications_statistics.route('/seven_day_aggregate')
 def get_notification_statistics_for_service_seven_day_aggregate(service_id):
-    data, errors = week_aggregate_notification_statistics_schema.load(request.args)
-    if errors:
-        return jsonify(result='error', message=errors), 400
+    data = week_aggregate_notification_statistics_schema.load(request.args).data
     date_from = data['date_from'] if 'date_from' in data else date(date.today().year, 4, 1)
     week_count = data['week_count'] if 'week_count' in data else 52
     stats = dao_get_7_day_agg_notification_statistics_for_service(
diff --git a/app/provider_details/rest.py b/app/provider_details/rest.py
index f976f1560..b075653f5 100644
--- a/app/provider_details/rest.py
+++ b/app/provider_details/rest.py
@@ -1,25 +1,31 @@
 from flask import Blueprint, jsonify, request
 
 from app.schemas import provider_details_schema
+
 from app.dao.provider_details_dao import (
     get_provider_details,
     get_provider_details_by_id,
-    get_provider_details_by_id,
     dao_update_provider_details
 )
 
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
+
 provider_details = Blueprint('provider_details', __name__)
+register_errors(provider_details)
 
 
 @provider_details.route('', methods=['GET'])
 def get_providers():
-    data, errors = provider_details_schema.dump(get_provider_details(), many=True)
+    data = provider_details_schema.dump(get_provider_details(), many=True).data
     return jsonify(provider_details=data)
 
 
 @provider_details.route('/<uuid:provider_details_id>', methods=['GET'])
 def get_provider_by_id(provider_details_id):
-    data, errors = provider_details_schema.dump(get_provider_details_by_id(provider_details_id))
+    data = provider_details_schema.dump(get_provider_details_by_id(provider_details_id)).data
     return jsonify(provider_details=data)
 
 
@@ -29,14 +35,12 @@ def update_provider_details(provider_details_id):
 
     current_data = dict(provider_details_schema.dump(fetched_provider_details).data.items())
     current_data.update(request.get_json())
-    update_dict, errors = provider_details_schema.load(current_data)
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    update_dict = provider_details_schema.load(current_data).data
 
     if "identifier" in request.get_json().keys():
-        return jsonify(message={
-            "identifier": ["Not permitted to be updated"]
-        }, result='error'), 400
+        message = "Not permitted to be updated"
+        errors = {'identifier': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
     dao_update_provider_details(update_dict)
     return jsonify(provider_details=provider_details_schema.dump(fetched_provider_details).data), 200
diff --git a/app/schemas.py b/app/schemas.py
index 07385df81..a9d39c5c6 100644
--- a/app/schemas.py
+++ b/app/schemas.py
@@ -1,13 +1,16 @@
-from datetime import date
+from datetime import (
+    datetime,
+    date
+)
 from flask_marshmallow.fields import fields
-from sqlalchemy.orm import load_only
 
 from marshmallow import (
     post_load,
     ValidationError,
     validates,
     validates_schema,
-    pre_load
+    pre_load,
+    pre_dump
 )
 from marshmallow_sqlalchemy import field_for
 
@@ -46,6 +49,7 @@ def _validate_not_in_future(dte, msg="Date cannot be in the future"):
 
 
 class BaseSchema(ma.ModelSchema):
+
     def __init__(self, load_json=False, *args, **kwargs):
         self.load_json = load_json
         super(BaseSchema, self).__init__(*args, **kwargs)
@@ -82,12 +86,14 @@ class UserSchema(BaseSchema):
         exclude = (
             "updated_at", "created_at", "user_to_service",
             "_password", "verify_codes")
+        strict = True
 
 
 class ProviderDetailsSchema(BaseSchema):
     class Meta:
         model = models.ProviderDetails
         exclude = ("provider_rates", "provider_stats")
+        strict = True
 
 
 class ServiceSchema(BaseSchema):
@@ -97,11 +103,13 @@ class ServiceSchema(BaseSchema):
     class Meta:
         model = models.Service
         exclude = ("updated_at", "created_at", "api_keys", "templates", "jobs", 'old_id')
+        strict = True
 
 
 class NotificationModelSchema(BaseSchema):
     class Meta:
         model = models.Notification
+        strict = True
 
 
 class BaseTemplateSchema(BaseSchema):
@@ -109,6 +117,7 @@ class BaseTemplateSchema(BaseSchema):
     class Meta:
         model = models.Template
         exclude = ("service_id", "jobs")
+        strict = True
 
 
 class TemplateSchema(BaseTemplateSchema):
@@ -142,6 +151,13 @@ class TemplateHistorySchema(BaseSchema):
 class NotificationsStatisticsSchema(BaseSchema):
     class Meta:
         model = models.NotificationStatistics
+        strict = True
+
+    @pre_dump
+    def handle_date_str(self, in_data):
+        if isinstance(in_data, dict) and 'day' in in_data:
+            in_data['day'] = datetime.strptime(in_data['day'], '%Y-%m-%d').date()
+        return in_data
 
 
 class ApiKeySchema(BaseSchema):
@@ -151,6 +167,7 @@ class ApiKeySchema(BaseSchema):
     class Meta:
         model = models.ApiKey
         exclude = ("service", "secret")
+        strict = True
 
 
 class JobSchema(BaseSchema):
@@ -161,13 +178,22 @@ class JobSchema(BaseSchema):
     class Meta:
         model = models.Job
         exclude = ('notifications',)
+        strict = True
 
 
 class RequestVerifyCodeSchema(ma.Schema):
+
+    class Meta:
+        strict = True
+
     to = fields.Str(required=False)
 
 
 class NotificationSchema(ma.Schema):
+
+    class Meta:
+        strict = True
+
     personalisation = fields.Dict(required=False)
 
 
@@ -225,12 +251,14 @@ class NotificationStatusSchema(BaseSchema):
 
     class Meta:
         model = models.Notification
+        strict = True
 
 
 class InvitedUserSchema(BaseSchema):
 
     class Meta:
         model = models.InvitedUser
+        strict = True
 
     @validates('email_address')
     def validate_to(self, value):
@@ -255,9 +283,14 @@ class PermissionSchema(BaseSchema):
     class Meta:
         model = models.Permission
         exclude = ("created_at",)
+        strict = True
 
 
 class EmailDataSchema(ma.Schema):
+
+    class Meta:
+        strict = True
+
     email = fields.Str(required=False)
 
     @validates('email')
@@ -269,6 +302,10 @@ class EmailDataSchema(ma.Schema):
 
 
 class NotificationsFilterSchema(ma.Schema):
+
+    class Meta:
+        strict = True
+
     template_type = fields.Nested(BaseTemplateSchema, only=['template_type'], many=True)
     status = fields.Nested(NotificationModelSchema, only=['status'], many=True)
     page = fields.Int(required=False)
@@ -309,6 +346,7 @@ class TemplateStatisticsSchema(BaseSchema):
 
     class Meta:
         model = models.TemplateStatistics
+        strict = True
 
 
 class ServiceHistorySchema(ma.Schema):
@@ -337,10 +375,14 @@ class ApiKeyHistorySchema(ma.Schema):
 class EventSchema(BaseSchema):
     class Meta:
         model = models.Event
+        strict = True
 
 
 class FromToDateSchema(ma.Schema):
 
+    class Meta:
+        strict = True
+
     date_from = fields.Date()
     date_to = fields.Date()
 
@@ -361,6 +403,10 @@ class FromToDateSchema(ma.Schema):
 
 
 class DaySchema(ma.Schema):
+
+    class Meta:
+        strict = True
+
     day = fields.Date(required=True)
 
     @validates('day')
@@ -370,6 +416,9 @@ class DaySchema(ma.Schema):
 
 class WeekAggregateNotificationStatisticsSchema(ma.Schema):
 
+    class Meta:
+        strict = True
+
     date_from = fields.Date()
     week_count = fields.Int()
 
diff --git a/app/service/rest.py b/app/service/rest.py
index 0d2da9cb0..1b01ec9a1 100644
--- a/app/service/rest.py
+++ b/app/service/rest.py
@@ -6,9 +6,9 @@ from datetime import (
 from flask import (
     jsonify,
     request,
-    abort,
     Blueprint
 )
+
 from sqlalchemy.orm.exc import NoResultFound
 
 from app.dao.api_key_dao import (
@@ -39,11 +39,12 @@ from app.schemas import (
     permission_schema
 )
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 service = Blueprint('service', __name__)
-
-
 register_errors(service)
 
 
@@ -54,7 +55,7 @@ def get_services():
         services = dao_fetch_all_services_by_user(user_id)
     else:
         services = dao_fetch_all_services()
-    data, errors = service_schema.dump(services, many=True)
+    data = service_schema.dump(services, many=True).data
     return jsonify(data=data)
 
 
@@ -66,7 +67,7 @@ def get_service_by_id(service_id):
     else:
         fetched = dao_fetch_service_by_id(service_id)
 
-    data, errors = service_schema.dump(fetched)
+    data = service_schema.dump(fetched).data
     return jsonify(data=data)
 
 
@@ -74,16 +75,12 @@ def get_service_by_id(service_id):
 def create_service():
     data = request.get_json()
     if not data.get('user_id', None):
-        return jsonify(result="error", message={'user_id': ['Missing data for required field.']}), 400
+        errors = {'user_id': ['Missing data for required field.']}
+        raise InvalidRequest(errors, status_code=400)
 
     user = get_model_users(data['user_id'])
-
     data.pop('user_id', None)
-    valid_service, errors = service_schema.load(request.get_json())
-
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    valid_service = service_schema.load(request.get_json()).data
     dao_create_service(valid_service, user)
     return jsonify(data=service_schema.dump(valid_service).data), 201
 
@@ -93,9 +90,7 @@ def update_service(service_id):
     fetched_service = dao_fetch_service_by_id(service_id)
     current_data = dict(service_schema.dump(fetched_service).data.items())
     current_data.update(request.get_json())
-    update_dict, errors = service_schema.load(current_data)
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    update_dict = service_schema.load(current_data).data
     dao_update_service(update_dict)
     return jsonify(data=service_schema.dump(fetched_service).data), 200
 
@@ -103,14 +98,9 @@ def update_service(service_id):
 @service.route('/<uuid:service_id>/api-key', methods=['POST'])
 def renew_api_key(service_id=None):
     fetched_service = dao_fetch_service_by_id(service_id=service_id)
-
-    valid_api_key, errors = api_key_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    valid_api_key = api_key_schema.load(request.get_json()).data
     valid_api_key.service = fetched_service
-
     save_model_api_key(valid_api_key)
-
     unsigned_api_key = get_unsigned_secret(valid_api_key.id)
     return jsonify(data=unsigned_api_key), 201
 
@@ -133,7 +123,8 @@ def get_api_keys(service_id, key_id=None):
         else:
             api_keys = get_model_api_keys(service_id=service_id)
     except NoResultFound:
-        return jsonify(result="error", message="API key not found for id: {}".format(service_id)), 404
+        error = "API key not found for id: {}".format(service_id)
+        raise InvalidRequest(error, status_code=404)
 
     return jsonify(apiKeys=api_key_schema.dump(api_keys, many=True).data), 200
 
@@ -141,7 +132,6 @@ def get_api_keys(service_id, key_id=None):
 @service.route('/<uuid:service_id>/users', methods=['GET'])
 def get_users_for_service(service_id):
     fetched = dao_fetch_service_by_id(service_id)
-
     result = user_schema.dump(fetched.users, many=True)
     return jsonify(data=result.data)
 
@@ -152,15 +142,12 @@ def add_user_to_service(service_id, user_id):
     user = get_model_users(user_id=user_id)
 
     if user in service.users:
-        return jsonify(result='error',
-                       message='User id: {} already part of service id: {}'.format(user_id, service_id)), 400
-
-    permissions, errors = permission_schema.load(request.get_json(), many=True)
-    if errors:
-        abort(400, errors)
+        error = 'User id: {} already part of service id: {}'.format(user_id, service_id)
+        raise InvalidRequest(error, status_code=400)
 
+    permissions = permission_schema.load(request.get_json(), many=True).data
     dao_add_user_to_service(service, user, permissions)
-    data, errors = service_schema.dump(service)
+    data = service_schema.dump(service).data
     return jsonify(data=data), 201
 
 
@@ -169,13 +156,13 @@ def remove_user_from_service(service_id, user_id):
     service = dao_fetch_service_by_id(service_id)
     user = get_model_users(user_id=user_id)
     if user not in service.users:
-        return jsonify(
-            result='error',
-            message='User not found'), 404
+        error = 'User not found'
+        raise InvalidRequest(error, status_code=404)
+
     elif len(service.users) == 1:
-        return jsonify(
-            result='error',
-            message='You cannot remove the only user for a service'), 400
+        error = 'You cannot remove the only user for a service'
+        raise InvalidRequest(error, status_code=400)
+
     dao_remove_user_from_service(service, user)
     return jsonify({}), 204
 
@@ -183,10 +170,7 @@ def remove_user_from_service(service_id, user_id):
 @service.route('/<uuid:service_id>/fragment/aggregate_statistics')
 def get_service_provider_aggregate_statistics(service_id):
     service = dao_fetch_service_by_id(service_id)
-    data, errors = from_to_date_schema.load(request.args)
-    if errors:
-        return jsonify(result='error', message=errors), 400
-
+    data = from_to_date_schema.load(request.args).data
     return jsonify(data=get_fragment_count(
         service,
         date_from=(data.pop('date_from') if 'date_from' in data else date.today()),
@@ -208,21 +192,15 @@ def get_service_history(service_id):
     )
 
     service_history = Service.get_history_model().query.filter_by(id=service_id).all()
-    service_data, errors = service_history_schema.dump(service_history, many=True)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-
+    service_data = service_history_schema.dump(service_history, many=True).data
     api_key_history = ApiKey.get_history_model().query.filter_by(service_id=service_id).all()
-
-    api_keys_data, errors = api_key_history_schema.dump(api_key_history, many=True)
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    api_keys_data = api_key_history_schema.dump(api_key_history, many=True).data
 
     template_history = Template.get_history_model().query.filter_by(service_id=service_id).all()
     template_data, errors = template_history_schema.dump(template_history, many=True)
 
     events = Event.query.all()
-    events_data, errors = event_schema.dump(events, many=True)
+    events_data = event_schema.dump(events, many=True).data
 
     data = {
         'service_history': service_data,
diff --git a/app/template/rest.py b/app/template/rest.py
index 168d483ea..dc285e9d1 100644
--- a/app/template/rest.py
+++ b/app/template/rest.py
@@ -19,36 +19,32 @@ from app.schemas import (template_schema, template_history_schema)
 
 template = Blueprint('template', __name__, url_prefix='/service/<uuid:service_id>/template')
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 register_errors(template)
 
 
 def _content_count_greater_than_limit(content, template_type):
     template = Template({'content': content, 'template_type': template_type})
-    if template_type == 'sms' and \
-       template.content_count > current_app.config.get('SMS_CHAR_COUNT_LIMIT'):
-        return True, jsonify(
-            result="error",
-            message={'content': ['Content has a character count greater than the limit of {}'.format(
-                current_app.config.get('SMS_CHAR_COUNT_LIMIT'))]}
-        )
-    return False, ''
+    return template_type == 'sms' and template.content_count > current_app.config.get('SMS_CHAR_COUNT_LIMIT')
 
 
 @template.route('', methods=['POST'])
 def create_template(service_id):
     fetched_service = dao_fetch_service_by_id(service_id=service_id)
-    new_template, errors = template_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
+    new_template = template_schema.load(request.get_json()).data
     new_template.service = fetched_service
     new_template.content = _strip_html(new_template.content)
-    over_limit, json_resp = _content_count_greater_than_limit(
-        new_template.content,
-        new_template.template_type)
+    over_limit = _content_count_greater_than_limit(new_template.content, new_template.template_type)
     if over_limit:
-        return json_resp, 400
+        char_count_limit = current_app.config.get('SMS_CHAR_COUNT_LIMIT')
+        message = 'Content has a character count greater than the limit of {}'.format(char_count_limit)
+        errors = {'content': [message]}
+        raise InvalidRequest(errors, status_code=400)
+
     dao_create_template(new_template)
     return jsonify(data=template_schema.dump(new_template).data), 201
 
@@ -65,14 +61,13 @@ def update_template(service_id, template_id):
     if _template_has_not_changed(current_data, updated_template):
         return jsonify(data=updated_template), 200
 
-    update_dict, errors = template_schema.load(updated_template)
-    if errors:
-        return jsonify(result="error", message=errors), 400
-    over_limit, json_resp = _content_count_greater_than_limit(
-        updated_template['content'],
-        fetched_template.template_type)
+    update_dict = template_schema.load(updated_template).data
+    over_limit = _content_count_greater_than_limit(updated_template['content'], fetched_template.template_type)
     if over_limit:
-        return json_resp, 400
+        char_count_limit = current_app.config.get('SMS_CHAR_COUNT_LIMIT')
+        message = 'Content has a character count greater than the limit of {}'.format(char_count_limit)
+        errors = {'content': [message]}
+        raise InvalidRequest(errors, status_code=400)
     dao_update_template(update_dict)
     return jsonify(data=template_schema.dump(update_dict).data), 200
 
@@ -80,39 +75,35 @@ def update_template(service_id, template_id):
 @template.route('', methods=['GET'])
 def get_all_templates_for_service(service_id):
     templates = dao_get_all_templates_for_service(service_id=service_id)
-    data, errors = template_schema.dump(templates, many=True)
+    data = template_schema.dump(templates, many=True).data
     return jsonify(data=data)
 
 
 @template.route('/<uuid:template_id>', methods=['GET'])
 def get_template_by_id_and_service_id(service_id, template_id):
     fetched_template = dao_get_template_by_id_and_service_id(template_id=template_id, service_id=service_id)
-    data, errors = template_schema.dump(fetched_template)
+    data = template_schema.dump(fetched_template).data
     return jsonify(data=data)
 
 
 @template.route('/<uuid:template_id>/version/<int:version>')
 def get_template_version(service_id, template_id, version):
-    data, errors = template_history_schema.dump(
+    data = template_history_schema.dump(
         dao_get_template_by_id_and_service_id(
             template_id=template_id,
             service_id=service_id,
             version=version
         )
-    )
-    if errors:
-        return jsonify(result='error', message=errors), 400
+    ).data
     return jsonify(data=data)
 
 
 @template.route('/<uuid:template_id>/versions')
 def get_template_versions(service_id, template_id):
-    data, errors = template_history_schema.dump(
+    data = template_history_schema.dump(
         dao_get_template_versions(service_id=service_id, template_id=template_id),
         many=True
-    )
-    if errors:
-        return jsonify(result='error', message=errors), 400
+    ).data
     return jsonify(data=data)
 
 
diff --git a/app/template_statistics/rest.py b/app/template_statistics/rest.py
index 1e46843c5..d4990ba04 100644
--- a/app/template_statistics/rest.py
+++ b/app/template_statistics/rest.py
@@ -15,7 +15,7 @@ template_statistics = Blueprint('template-statistics',
                                 __name__,
                                 url_prefix='/service/<service_id>/template-statistics')
 
-from app.errors import register_errors, InvalidData
+from app.errors import register_errors, InvalidRequest
 
 register_errors(template_statistics)
 
@@ -28,20 +28,16 @@ def get_template_statistics_for_service(service_id):
         except ValueError as e:
             error = '{} is not an integer'.format(request.args['limit_days'])
             message = {'limit_days': [error]}
-            raise InvalidData(message, status_code=400)
+            raise InvalidRequest(message, status_code=400)
     else:
         limit_days = None
     stats = dao_get_template_statistics_for_service(service_id, limit_days=limit_days)
-    data, errors = template_statistics_schema.dump(stats, many=True)
-    if errors:
-        raise InvalidData(errors, status_code=400)
+    data = template_statistics_schema.dump(stats, many=True).data
     return jsonify(data=data)
 
 
 @template_statistics.route('/<template_id>')
 def get_template_statistics_for_template_id(service_id, template_id):
     stats = dao_get_template_statistics_for_template(template_id)
-    data, errors = template_statistics_schema.dump(stats, many=True)
-    if errors:
-        raise InvalidData(errors, status_code=400)
+    data = template_statistics_schema.dump(stats, many=True).data
     return jsonify(data=data)
diff --git a/app/user/rest.py b/app/user/rest.py
index 46668b98c..93d7f1d9e 100644
--- a/app/user/rest.py
+++ b/app/user/rest.py
@@ -1,7 +1,7 @@
 import json
 import uuid
 from datetime import datetime
-from flask import (jsonify, request, abort, Blueprint, current_app)
+from flask import (jsonify, request, Blueprint, current_app)
 from app import encryption, DATETIME_FORMAT
 from app.dao.users_dao import (
     get_model_users,
@@ -28,9 +28,13 @@ from app.schemas import (
 from app.celery.tasks import (
     send_sms,
     email_reset_password,
-    send_email)
+    send_email
+)
 
-from app.errors import register_errors
+from app.errors import (
+    register_errors,
+    InvalidRequest
+)
 
 user = Blueprint('user', __name__)
 register_errors(user)
@@ -43,9 +47,7 @@ def create_user():
     # TODO password policy, what is valid password
     if not req_json.get('password', None):
         errors.update({'password': ['Missing data for required field.']})
-        return jsonify(result="error", message=errors), 400
-    if errors:
-        return jsonify(result="error", message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
     save_model_user(user_to_create, pwd=req_json.get('password'))
     return jsonify(data=user_schema.dump(user_to_create).data), 201
 
@@ -60,11 +62,9 @@ def update_user(user_id):
     # but would be good to have the same validation here.
     if pwd is not None and not pwd:
         errors.update({'password': ['Invalid data for field']})
-    if errors:
-        return jsonify(result="error", message=errors), 400
-    status_code = 200
+        raise InvalidRequest(errors, status_code=400)
     save_model_user(user_to_update, update_dict=update_dct, pwd=pwd)
-    return jsonify(data=user_schema.dump(user_to_update).data), status_code
+    return jsonify(data=user_schema.dump(user_to_update).data), 200
 
 
 @user.route('/<uuid:user_id>/verify/password', methods=['POST'])
@@ -75,9 +75,10 @@ def verify_user_password(user_id):
     try:
         txt_pwd = request.get_json()['password']
     except KeyError:
-        return jsonify(
-            result="error",
-            message={'password': ['Required field missing data']}), 400
+        message = 'Required field missing data'
+        errors = {'password': [message]}
+        raise InvalidRequest(errors, status_code=400)
+
     if user_to_verify.check_password(txt_pwd):
         user_to_verify.logged_in_at = datetime.utcnow()
         save_model_user(user_to_verify)
@@ -85,7 +86,9 @@ def verify_user_password(user_id):
         return jsonify({}), 204
     else:
         increment_failed_login_count(user_to_verify)
-        return jsonify(result='error', message={'password': ['Incorrect password']}), 400
+        message = 'Incorrect password'
+        errors = {'password': [message]}
+        raise InvalidRequest(errors, status_code=400)
 
 
 @user.route('/<uuid:user_id>/verify/code', methods=['POST'])
@@ -105,12 +108,13 @@ def verify_user_code(user_id):
     except KeyError:
         errors.update({'code_type': ['Required field missing data']})
     if errors:
-        return jsonify(result="error", message=errors), 400
+        raise InvalidRequest(errors, status_code=400)
+
     code = get_user_code(user_to_verify, txt_code, txt_type)
     if not code:
-        return jsonify(result="error", message="Code not found"), 404
+        raise InvalidRequest("Code not found", status_code=404)
     if datetime.utcnow() > code.expiry_datetime or code.code_used:
-        return jsonify(result="error", message="Code has expired"), 400
+        raise InvalidRequest("Code has expired", status_code=400)
     use_user_code(code.id)
     return jsonify({}), 204
 
@@ -119,8 +123,6 @@ def verify_user_code(user_id):
 def send_user_sms_code(user_id):
     user_to_send_to = get_model_users(user_id=user_id)
     verify_code, errors = request_verify_code_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
 
     secret_code = create_secret_code()
     create_user_code(user_to_send_to, secret_code, 'sms')
@@ -150,8 +152,6 @@ def send_user_sms_code(user_id):
 def send_user_email_verification(user_id):
     user_to_send_to = get_model_users(user_id=user_id)
     verify_code, errors = request_verify_code_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
 
     secret_code = create_secret_code()
     create_user_code(user_to_send_to, secret_code, 'email')
@@ -191,8 +191,7 @@ def set_permissions(user_id, service_id):
     user = get_model_users(user_id=user_id)
     service = dao_fetch_service_by_id(service_id=service_id)
     permissions, errors = permission_schema.load(request.get_json(), many=True)
-    if errors:
-        abort(400, errors)
+
     for p in permissions:
         p.user = user
         p.service = service
@@ -204,7 +203,8 @@ def set_permissions(user_id, service_id):
 def get_by_email():
     email = request.args.get('email')
     if not email:
-        return jsonify(result="error", message="invalid request"), 400
+        error = 'Invalid request. Email query string param required'
+        raise InvalidRequest(error, status_code=400)
     fetched_user = get_user_by_email(email)
     result = user_schema.dump(fetched_user)
 
@@ -214,8 +214,6 @@ def get_by_email():
 @user.route('/reset-password', methods=['POST'])
 def send_user_reset_password():
     email, errors = email_data_request_schema.load(request.get_json())
-    if errors:
-        return jsonify(result="error", message=errors), 400
 
     user_to_send_to = get_user_by_email(email['email'])
 
diff --git a/tests/app/dao/test_templates_dao.py b/tests/app/dao/test_templates_dao.py
index ad4b4372e..82b943963 100644
--- a/tests/app/dao/test_templates_dao.py
+++ b/tests/app/dao/test_templates_dao.py
@@ -267,6 +267,6 @@ def test_get_template_versions(sample_template):
             assert x.content == 'new version'
         else:
             assert x.content == original_content
-    from app.schemas import (template_history_schema)
+    from app.schemas import template_history_schema
     v = template_history_schema.load(versions, many=True)
     assert v.__len__() == 2
diff --git a/tests/app/user/test_rest.py b/tests/app/user/test_rest.py
index 82b93d4cb..4f6286f6f 100644
--- a/tests/app/user/test_rest.py
+++ b/tests/app/user/test_rest.py
@@ -296,7 +296,7 @@ def test_get_user_by_email_bad_url_returns_404(notify_api,
             assert resp.status_code == 400
             json_resp = json.loads(resp.get_data(as_text=True))
             assert json_resp['result'] == 'error'
-            assert json_resp['message'] == 'invalid request'
+            assert json_resp['message'] == 'Invalid request. Email query string param required'
 
 
 def test_get_user_with_permissions(notify_api,