diff --git a/.gitignore b/.gitignore
index ee44e23a..0f58a6d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,6 +18,7 @@ develop-eggs
 pip-log.txt
 
 # Unit test / coverage reports
+.pytest_cache/
 .coverage
 .tox
 
diff --git a/mws/apis/inbound_shipments.py b/mws/apis/inbound_shipments.py
index 1792cc2e..b4b395cf 100644
--- a/mws/apis/inbound_shipments.py
+++ b/mws/apis/inbound_shipments.py
@@ -570,9 +570,6 @@ def list_inbound_shipments(self, shipment_ids=None, shipment_statuses=None,
         Docs:
         http://docs.developer.amazonservices.com/en_US/fba_inbound/FBAInbound_ListInboundShipments.html
         """
-        last_updated_after = utils.dt_iso_or_none(last_updated_after)
-        last_updated_before = utils.dt_iso_or_none(last_updated_before)
-
         data = {
             'Action': 'ListInboundShipments',
             'LastUpdatedAfter': last_updated_after,
@@ -605,9 +602,6 @@ def list_inbound_shipment_items(self, shipment_id=None, last_updated_after=None,
         Docs:
         http://docs.developer.amazonservices.com/en_US/fba_inbound/FBAInbound_ListInboundShipmentItems.html
         """
-        last_updated_after = utils.dt_iso_or_none(last_updated_after)
-        last_updated_before = utils.dt_iso_or_none(last_updated_before)
-
         data = {
             'Action': 'ListInboundShipmentItems',
             'ShipmentId': shipment_id,
diff --git a/mws/apis/reports.py b/mws/apis/reports.py
index dc5f4141..adfa5862 100644
--- a/mws/apis/reports.py
+++ b/mws/apis/reports.py
@@ -3,7 +3,7 @@
 """
 from __future__ import absolute_import
 
-import mws
+from ..mws import MWS
 from .. import utils
 from ..decorators import next_token_action
 
@@ -11,7 +11,7 @@
 # TODO Add Schedule enumerations as constants
 
 
-class Reports(mws.MWS):
+class Reports(MWS):
     """
     Amazon MWS Reports API
 
diff --git a/mws/mws.py b/mws/mws.py
index a1e833f3..e0e3651d 100644
--- a/mws/mws.py
+++ b/mws/mws.py
@@ -76,16 +76,31 @@ def calc_request_description(params):
     """
     description_items = []
     for item in sorted(params.keys()):
-        encoded_val = quote(str(params[item]), safe='-_.~')
+        encoded_val = params[item]
         description_items.append('{}={}'.format(item, encoded_val))
     return '&'.join(description_items)
 
 
-def remove_empty(dict_):
-    """
-    Returns dict_ with all empty values removed.
-    """
-    return {k: v for k, v in dict_.items() if v}
+def clean_params(params):
+    """Input cleanup and prevent a lot of common input mistakes."""
+    # silently remove parameter where values are empty
+    params = {k: v for k, v in params.items() if v}
+
+    params_enc = dict()
+    for key, value in params.items():
+        if isinstance(value, (dict, list, set, tuple)):
+            message = 'expected string or datetime datatype, got {},'\
+                'for key {} and value {}'.format(
+                    type(value), key, str(value))
+            raise MWSError(message)
+        if isinstance(value, (datetime.datetime, datetime.date)):
+            value = value.isoformat()
+        if isinstance(value, bool):
+            value = str(value).lower()
+        value = str(value)
+
+        params_enc[key] = quote(value, safe='-_.~')
+    return params_enc
 
 
 def remove_namespace(xml):
@@ -121,6 +136,7 @@ class DictWrapper(object):
     # TODO create a base class for DictWrapper and DataWrapper with all the keys we expect in responses.
     # This will make it easier to use either class in place of each other.
     # Either this, or pile everything into DataWrapper and make it able to handle all cases.
+
     def __init__(self, xml, rootkey=None):
         self.original = xml
         self.response = None
@@ -142,6 +158,7 @@ class DataWrapper(object):
     """
     Text wrapper in charge of validating the hash sent by Amazon.
     """
+
     def __init__(self, data, header):
         self.original = data
         self.response = None
@@ -246,18 +263,11 @@ def make_request(self, extra_data, method="GET", **kwargs):
         """
         Make request to Amazon MWS API with these parameters
         """
-        # Remove all keys with an empty value because
-        # Amazon's MWS does not allow such a thing.
-        extra_data = remove_empty(extra_data)
-
-        # convert all Python date/time objects to isoformat
-        for key, value in extra_data.items():
-            if isinstance(value, (datetime.datetime, datetime.date)):
-                extra_data[key] = value.isoformat()
-
         params = self.get_default_params()
         proxies = self.get_proxies()
         params.update(extra_data)
+        params = clean_params(params)
+
         if self._test_request_params:
             # Testing method: return the params from this request before the request is made.
             return params
@@ -279,7 +289,8 @@ def make_request(self, extra_data, method="GET", **kwargs):
             # My answer is, here i have to get the url parsed string of params in order to sign it, so
             # if i pass the params dict as params to request, request will repeat that step because it will need
             # to convert the dict to a url parsed string, so why do it twice if i can just pass the full url :).
-            response = request(method, url, data=kwargs.get('body', ''), headers=headers, proxies=proxies)
+            response = request(method, url, data=kwargs.get(
+                'body', ''), headers=headers, proxies=proxies)
             response.raise_for_status()
             # When retrieving data from the response object,
             # be aware that response.content returns the content in bytes while response.text calls
diff --git a/mws/utils.py b/mws/utils.py
index 25a71e8a..57872627 100644
--- a/mws/utils.py
+++ b/mws/utils.py
@@ -27,6 +27,7 @@ class ObjectDict(dict):
     >>> a.water
     'water'
     """
+
     def __init__(self, initd=None):
         if initd is None:
             initd = {}
@@ -271,22 +272,6 @@ def unique_list_order_preserved(seq):
     return [x for x in seq if not (x in seen or seen_add(x))]
 
 
-def dt_iso_or_none(dt_obj):
-    """
-    If dt_obj is a datetime, return isoformat()
-    TODO: if dt_obj is a string in iso8601 already, return it back
-    Otherwise, return None
-    """
-    # If d is a datetime object, format it to iso and return
-    if isinstance(dt_obj, datetime.datetime):
-        return dt_obj.isoformat()
-
-    # TODO: if dt_obj is a string in iso8601 already, return it
-
-    # none of the above: return None
-    return None
-
-
 def get_utc_timestamp():
     """
     Returns the current UTC timestamp in ISO-8601 format.
diff --git a/tests/request_methods/test_feeds.py b/tests/request_methods/test_feeds.py
index 736f128b..c3354813 100644
--- a/tests/request_methods/test_feeds.py
+++ b/tests/request_methods/test_feeds.py
@@ -4,7 +4,7 @@
 import unittest
 import datetime
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date
 
 
 class FeedsTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -12,6 +12,7 @@ class FeedsTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Feeds.
     """
     # TODO: Add remaining methods for Feeds
+
     def setUp(self):
         self.api = mws.Feeds(
             self.CREDENTIAL_ACCESS,
@@ -33,9 +34,9 @@ def test_get_feed_submission_list(self):
         GetFeedSubmissionList operation
         """
         from_date = datetime.datetime.utcnow()
-        from_date_stamp = from_date.isoformat()
+        from_date_stamp = transform_date(from_date)
         to_date = datetime.datetime.utcnow()
-        to_date_stamp = to_date.isoformat()
+        to_date_stamp = transform_date(to_date)
         feed_ids = [
             '1058369303',
             '1228369302',
@@ -61,7 +62,7 @@ def test_get_feed_submission_list(self):
         self.assertEqual(params['Action'], 'GetFeedSubmissionList')
         self.assertEqual(params['SubmittedFromDate'], from_date_stamp)
         self.assertEqual(params['SubmittedToDate'], to_date_stamp)
-        self.assertEqual(params['MaxCount'], max_count)
+        self.assertEqual(params['MaxCount'], str(max_count))
         self.assertEqual(params['FeedSubmissionIdList.Id.1'], feed_ids[0])
         self.assertEqual(params['FeedSubmissionIdList.Id.2'], feed_ids[1])
         self.assertEqual(params['FeedTypeList.Type.1'], feed_types[0])
@@ -94,9 +95,9 @@ def test_get_feed_submission_count(self):
         GetFeedSubmissionCount operation
         """
         from_date = datetime.datetime.utcnow()
-        from_date_stamp = from_date.isoformat()
+        from_date_stamp = transform_date(from_date)
         to_date = datetime.datetime.utcnow()
-        to_date_stamp = to_date.isoformat()
+        to_date_stamp = transform_date(to_date)
         feed_types = [
             '_POST_PRODUCT_OVERRIDES_DATA_',
             '_POST_FLAT_FILE_FULFILLMENT_ORDER_CANCELLATION_REQUEST_DATA_',
@@ -125,9 +126,9 @@ def test_cancel_feed_submissions(self):
         CancelFeedSubmissions operation
         """
         from_date = datetime.datetime.utcnow()
-        from_date_stamp = from_date.isoformat()
+        from_date_stamp = transform_date(from_date)
         to_date = datetime.datetime.utcnow()
-        to_date_stamp = to_date.isoformat()
+        to_date_stamp = transform_date(to_date)
         feed_ids = [
             'SUB63kvutS',
             'l8dM04jxGD',
diff --git a/tests/request_methods/test_finances.py b/tests/request_methods/test_finances.py
index 1724e8ba..d3c7acaf 100644
--- a/tests/request_methods/test_finances.py
+++ b/tests/request_methods/test_finances.py
@@ -4,7 +4,7 @@
 import unittest
 import datetime
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date
 
 
 class FinancesTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -12,6 +12,7 @@ class FinancesTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Finances.
     """
     # TODO: Add remaining methods for Finances
+
     def setUp(self):
         self.api = mws.Finances(
             self.CREDENTIAL_ACCESS,
@@ -26,9 +27,7 @@ def test_list_financial_event_groups(self):
         ListFinancialEventGroups operation.
         """
         created_after = datetime.datetime.utcnow()
-        created_after_stamp = created_after.isoformat()
         created_before = datetime.datetime.utcnow()
-        created_before_stamp = created_before.isoformat()
         max_results = 659
         params = self.api.list_financial_event_groups(
             created_after=created_after,
@@ -37,9 +36,11 @@ def test_list_financial_event_groups(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListFinancialEventGroups')
-        self.assertEqual(params['FinancialEventGroupStartedAfter'], created_after_stamp)
-        self.assertEqual(params['FinancialEventGroupStartedBefore'], created_before_stamp)
-        self.assertEqual(params['MaxResultsPerPage'], max_results)
+        self.assertEqual(params['FinancialEventGroupStartedAfter'],
+                         transform_date(created_after))
+        self.assertEqual(params['FinancialEventGroupStartedBefore'],
+                         transform_date(created_before))
+        self.assertEqual(params['MaxResultsPerPage'], str(max_results))
 
     def test_list_financial_event_groups_by_next_token(self):
         """
@@ -66,9 +67,7 @@ def test_list_financial_events(self):
         ListFinancialEvents operation.
         """
         posted_after = datetime.datetime.utcnow()
-        posted_after_stamp = posted_after.isoformat()
         posted_before = datetime.datetime.utcnow()
-        posted_before_stamp = posted_before.isoformat()
         amazon_order_id = '123-4567890-1234567'
         financial_event_group_id = '22YgYW55IGNhcm5hbCBwbGVhEXAMPLE'
         max_results = 156
@@ -83,9 +82,9 @@ def test_list_financial_events(self):
         self.assertEqual(params['Action'], 'ListFinancialEvents')
         self.assertEqual(params['FinancialEventGroupId'], financial_event_group_id)
         self.assertEqual(params['AmazonOrderId'], amazon_order_id)
-        self.assertEqual(params['PostedAfter'], posted_after_stamp)
-        self.assertEqual(params['PostedBefore'], posted_before_stamp)
-        self.assertEqual(params['MaxResultsPerPage'], max_results)
+        self.assertEqual(params['PostedAfter'], transform_date(posted_after))
+        self.assertEqual(params['PostedBefore'], transform_date(posted_before))
+        self.assertEqual(params['MaxResultsPerPage'], str(max_results))
 
     def test_list_financial_events_by_next_token(self):
         """
diff --git a/tests/request_methods/test_inboundshipments.py b/tests/request_methods/test_inboundshipments.py
index eb78d766..8042468f 100644
--- a/tests/request_methods/test_inboundshipments.py
+++ b/tests/request_methods/test_inboundshipments.py
@@ -6,13 +6,15 @@
 import mws
 from mws.apis.inbound_shipments import parse_item_args
 from mws.mws import MWSError
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date, transform_bool
+from .utils import transform_string
 
 
 class ParseItemArgsTestCase(unittest.TestCase):
     """
     Test cases that ensure `parse_item_args` raises exceptions where appropriate.
     """
+
     def test_empty_args_list(self):
         """
         Should raise `MWSError` for an empty set of arguments.
@@ -154,6 +156,7 @@ class SetShipFromAddressTestCase(unittest.TestCase):
     """
     Test case covering msw.InboundShipments.set_ship_from_address
     """
+
     def setUp(self):
         self.inbound = mws.InboundShipments('', '', '')
 
@@ -279,6 +282,7 @@ class FBAShipmentHandlingTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for InboundShipments involving FBA shipment handling.
     These cases require `from_address` to be set, while others do not.
     """
+
     def setUp(self):
         self.addr = {
             'name': 'Roland Deschain',
@@ -331,18 +335,24 @@ def test_create_inbound_shipment_plan(self):
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'CreateInboundShipmentPlan')
         self.assertEqual(params['ShipToCountryCode'], country_code)
-        self.assertEqual(params['ShipToCountrySubdivisionCode'], subdivision_code)
+        self.assertEqual(params['ShipToCountrySubdivisionCode'], transform_string(subdivision_code))
         self.assertEqual(params['LabelPrepPreference'], label_preference)
         # from_address expanded
-        self.assertEqual(params['ShipFromAddress.Name'], self.addr['name'])
-        self.assertEqual(params['ShipFromAddress.AddressLine1'], self.addr['address_1'])
-        self.assertEqual(params['ShipFromAddress.City'], self.addr['city'])
-        self.assertEqual(params['ShipFromAddress.CountryCode'], self.addr['country'])
+        self.assertEqual(params['ShipFromAddress.Name'], transform_string(self.addr['name']))
+        self.assertEqual(params['ShipFromAddress.AddressLine1'],
+                         transform_string(self.addr['address_1']))
+        self.assertEqual(params['ShipFromAddress.City'], transform_string(self.addr['city']))
+        self.assertEqual(params['ShipFromAddress.CountryCode'],
+                         transform_string(self.addr['country']))
         # item data
-        self.assertEqual(params['InboundShipmentPlanRequestItems.member.1.SellerSKU'], items[0]['sku'])
-        self.assertEqual(params['InboundShipmentPlanRequestItems.member.1.Quantity'], items[0]['quantity'])
-        self.assertEqual(params['InboundShipmentPlanRequestItems.member.2.SellerSKU'], items[1]['sku'])
-        self.assertEqual(params['InboundShipmentPlanRequestItems.member.2.Quantity'], items[1]['quantity'])
+        self.assertEqual(
+            params['InboundShipmentPlanRequestItems.member.1.SellerSKU'], items[0]['sku'])
+        self.assertEqual(
+            params['InboundShipmentPlanRequestItems.member.1.Quantity'], str(items[0]['quantity']))
+        self.assertEqual(
+            params['InboundShipmentPlanRequestItems.member.2.SellerSKU'], items[1]['sku'])
+        self.assertEqual(
+            params['InboundShipmentPlanRequestItems.member.2.Quantity'], str(items[1]['quantity']))
 
     def test_create_inbound_shipment_exceptions(self):
         """
@@ -411,22 +421,35 @@ def test_create_inbound_shipment(self):
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'CreateInboundShipment')
         self.assertEqual(params['ShipmentId'], shipment_id)
-        self.assertEqual(params['InboundShipmentHeader.ShipmentName'], shipment_name)
-        self.assertEqual(params['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
+        self.assertEqual(params['InboundShipmentHeader.ShipmentName'],
+                         transform_string(shipment_name))
+        self.assertEqual(
+            params['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
         self.assertEqual(params['InboundShipmentHeader.LabelPrepPreference'], label_preference)
-        self.assertEqual(params['InboundShipmentHeader.AreCasesRequired'], case_required)
+        self.assertEqual(params['InboundShipmentHeader.AreCasesRequired'],
+                         transform_bool(case_required))
         self.assertEqual(params['InboundShipmentHeader.ShipmentStatus'], shipment_status)
-        self.assertEqual(params['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
+        self.assertEqual(
+            params['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
         # from_address
-        self.assertEqual(params['InboundShipmentHeader.ShipFromAddress.Name'], self.addr['name'])
-        self.assertEqual(params['InboundShipmentHeader.ShipFromAddress.AddressLine1'], self.addr['address_1'])
-        self.assertEqual(params['InboundShipmentHeader.ShipFromAddress.City'], self.addr['city'])
-        self.assertEqual(params['InboundShipmentHeader.ShipFromAddress.CountryCode'], self.addr['country'])
+        self.assertEqual(params['InboundShipmentHeader.ShipFromAddress.Name'],
+                         transform_string(self.addr['name']))
+        self.assertEqual(
+            params['InboundShipmentHeader.ShipFromAddress.AddressLine1'],
+            transform_string(self.addr['address_1']))
+        self.assertEqual(
+            params['InboundShipmentHeader.ShipFromAddress.City'],
+            transform_string(self.addr['city']))
+        self.assertEqual(
+            params['InboundShipmentHeader.ShipFromAddress.CountryCode'],
+            transform_string(self.addr['country']))
         # item data
         self.assertEqual(params['InboundShipmentItems.member.1.SellerSKU'], items[0]['sku'])
-        self.assertEqual(params['InboundShipmentItems.member.1.QuantityShipped'], items[0]['quantity'])
+        self.assertEqual(
+            params['InboundShipmentItems.member.1.QuantityShipped'], str(items[0]['quantity']))
         self.assertEqual(params['InboundShipmentItems.member.2.SellerSKU'], items[1]['sku'])
-        self.assertEqual(params['InboundShipmentItems.member.2.QuantityShipped'], items[1]['quantity'])
+        self.assertEqual(
+            params['InboundShipmentItems.member.2.QuantityShipped'], str(items[1]['quantity']))
 
     def test_update_inbound_shipment_exceptions(self):
         """
@@ -488,22 +511,35 @@ def test_update_inbound_shipment(self):
         self.assert_common_params(params_1)
         self.assertEqual(params_1['Action'], 'UpdateInboundShipment')
         self.assertEqual(params_1['ShipmentId'], shipment_id)
-        self.assertEqual(params_1['InboundShipmentHeader.ShipmentName'], shipment_name)
-        self.assertEqual(params_1['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
+        self.assertEqual(params_1['InboundShipmentHeader.ShipmentName'],
+                         transform_string(shipment_name))
+        self.assertEqual(
+            params_1['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
         self.assertEqual(params_1['InboundShipmentHeader.LabelPrepPreference'], label_preference)
-        self.assertEqual(params_1['InboundShipmentHeader.AreCasesRequired'], case_required)
+        self.assertEqual(params_1['InboundShipmentHeader.AreCasesRequired'],
+                         transform_bool(case_required))
         self.assertEqual(params_1['InboundShipmentHeader.ShipmentStatus'], shipment_status)
-        self.assertEqual(params_1['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
+        self.assertEqual(
+            params_1['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
         # from_address
-        self.assertEqual(params_1['InboundShipmentHeader.ShipFromAddress.Name'], self.addr['name'])
-        self.assertEqual(params_1['InboundShipmentHeader.ShipFromAddress.AddressLine1'], self.addr['address_1'])
-        self.assertEqual(params_1['InboundShipmentHeader.ShipFromAddress.City'], self.addr['city'])
-        self.assertEqual(params_1['InboundShipmentHeader.ShipFromAddress.CountryCode'], self.addr['country'])
+        self.assertEqual(
+            params_1['InboundShipmentHeader.ShipFromAddress.Name'],
+            transform_string(self.addr['name']))
+        self.assertEqual(
+            params_1['InboundShipmentHeader.ShipFromAddress.AddressLine1'],
+            transform_string(self.addr['address_1']))
+        self.assertEqual(
+            params_1['InboundShipmentHeader.ShipFromAddress.City'],
+            transform_string(self.addr['city']))
+        self.assertEqual(
+            params_1['InboundShipmentHeader.ShipFromAddress.CountryCode'], self.addr['country'])
         # item data
         self.assertEqual(params_1['InboundShipmentItems.member.1.SellerSKU'], items[0]['sku'])
-        self.assertEqual(params_1['InboundShipmentItems.member.1.QuantityShipped'], items[0]['quantity'])
+        self.assertEqual(
+            params_1['InboundShipmentItems.member.1.QuantityShipped'], str(items[0]['quantity']))
         self.assertEqual(params_1['InboundShipmentItems.member.2.SellerSKU'], items[1]['sku'])
-        self.assertEqual(params_1['InboundShipmentItems.member.2.QuantityShipped'], items[1]['quantity'])
+        self.assertEqual(
+            params_1['InboundShipmentItems.member.2.QuantityShipped'], str(items[1]['quantity']))
         # Additional case: no items required. Params should have no Items keys if not provided
         params_2 = self.api.update_inbound_shipment(
             shipment_id=shipment_id,
@@ -517,17 +553,26 @@ def test_update_inbound_shipment(self):
         self.assert_common_params(params_1)
         self.assertEqual(params_2['Action'], 'UpdateInboundShipment')
         self.assertEqual(params_2['ShipmentId'], shipment_id)
-        self.assertEqual(params_2['InboundShipmentHeader.ShipmentName'], shipment_name)
-        self.assertEqual(params_2['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
+        self.assertEqual(params_2['InboundShipmentHeader.ShipmentName'],
+                         transform_string(shipment_name))
+        self.assertEqual(
+            params_2['InboundShipmentHeader.DestinationFulfillmentCenterId'], destination)
         self.assertEqual(params_2['InboundShipmentHeader.LabelPrepPreference'], label_preference)
-        self.assertEqual(params_2['InboundShipmentHeader.AreCasesRequired'], case_required)
+        self.assertEqual(params_2['InboundShipmentHeader.AreCasesRequired'],
+                         transform_bool(case_required))
         self.assertEqual(params_2['InboundShipmentHeader.ShipmentStatus'], shipment_status)
-        self.assertEqual(params_2['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
+        self.assertEqual(
+            params_2['InboundShipmentHeader.IntendedBoxContentsSource'], box_contents_source)
         # from_address
-        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.Name'], self.addr['name'])
-        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.AddressLine1'], self.addr['address_1'])
-        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.City'], self.addr['city'])
-        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.CountryCode'], self.addr['country'])
+        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.Name'],
+                         transform_string(self.addr['name']))
+        self.assertEqual(
+            params_2['InboundShipmentHeader.ShipFromAddress.AddressLine1'],
+            transform_string(self.addr['address_1']))
+        self.assertEqual(params_2['InboundShipmentHeader.ShipFromAddress.City'],
+                         transform_string(self.addr['city']))
+        self.assertEqual(
+            params_2['InboundShipmentHeader.ShipFromAddress.CountryCode'], self.addr['country'])
         # items keys should not be present
         param_item_keys = [x for x in params_2.keys() if x.startswith('InboundShipmentItems')]
         # list should be empty, because no keys should be present
@@ -539,6 +584,7 @@ class InboundShipmentsRequestsTestCase(unittest.TestCase, CommonRequestTestTools
     Test cases for InboundShipments requests that do not involve FBA shipment handling
     and do not require `from_address` to be set.
     """
+
     def setUp(self):
         self.api = mws.InboundShipments(
             self.CREDENTIAL_ACCESS,
@@ -631,7 +677,7 @@ def test_confirm_preorder(self):
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ConfirmPreorder')
         self.assertEqual(params['ShipmentId'], shipment_id)
-        self.assertEqual(params['NeedByDate'], need_by_date.isoformat())
+        self.assertEqual(params['NeedByDate'], transform_date(need_by_date))
 
     def test_get_prep_instructions_for_sku(self):
         """
@@ -777,7 +823,7 @@ def test_get_package_labels(self):
         self.assertEqual(params['Action'], 'GetPackageLabels')
         self.assertEqual(params['ShipmentId'], shipment_id)
         self.assertEqual(params['PageType'], page_type)
-        self.assertEqual(params['NumberOfPackages'], num_labels)
+        self.assertEqual(params['NumberOfPackages'], str(num_labels))
 
     def test_get_unique_package_labels(self):
         """
@@ -830,7 +876,7 @@ def test_get_pallet_labels(self):
         self.assertEqual(params['Action'], 'GetPalletLabels')
         self.assertEqual(params['ShipmentId'], shipment_id)
         self.assertEqual(params['PageType'], page_type)
-        self.assertEqual(params['NumberOfPallets'], num_labels)
+        self.assertEqual(params['NumberOfPallets'], str(num_labels))
 
     def test_get_bill_of_lading(self):
         """
@@ -866,8 +912,8 @@ def test_list_inbound_shipments(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListInboundShipments')
-        self.assertEqual(params['LastUpdatedBefore'], last_updated_before.isoformat())
-        self.assertEqual(params['LastUpdatedAfter'], last_updated_after.isoformat())
+        self.assertEqual(params['LastUpdatedBefore'], transform_date(last_updated_before))
+        self.assertEqual(params['LastUpdatedAfter'], transform_date(last_updated_after))
         self.assertEqual(params['ShipmentStatusList.member.1'], shipment_statuses[0])
         self.assertEqual(params['ShipmentStatusList.member.2'], shipment_statuses[1])
         self.assertEqual(params['ShipmentIdList.member.1'], shipment_ids[0])
@@ -908,8 +954,8 @@ def test_list_inbound_shipment_items(self):
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListInboundShipmentItems')
         self.assertEqual(params['ShipmentId'], shipment_id)
-        self.assertEqual(params['LastUpdatedBefore'], last_updated_before.isoformat())
-        self.assertEqual(params['LastUpdatedAfter'], last_updated_after.isoformat())
+        self.assertEqual(params['LastUpdatedBefore'], transform_date(last_updated_before))
+        self.assertEqual(params['LastUpdatedAfter'], transform_date(last_updated_after))
 
     def test_list_inbound_shipment_items_by_next_token(self):
         """
diff --git a/tests/request_methods/test_inventory.py b/tests/request_methods/test_inventory.py
index 59a9d9a1..83572c1f 100644
--- a/tests/request_methods/test_inventory.py
+++ b/tests/request_methods/test_inventory.py
@@ -4,13 +4,14 @@
 import unittest
 import datetime
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date
 
 
 class InventoryTestCase(unittest.TestCase, CommonRequestTestTools):
     """
     Test cases for Inventory.
     """
+
     def setUp(self):
         self.api = mws.Inventory(
             self.CREDENTIAL_ACCESS,
@@ -25,13 +26,12 @@ def test_list_inventory_supply(self):
         ListInventorySupply operation
         """
         now = datetime.datetime.utcnow()
-        now_timestamp = now.isoformat()
         skus = ['thing1', 'thing2']
         response_group = 'Detailed'
         params = self.api.list_inventory_supply(skus, now, response_group=response_group)
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListInventorySupply')
-        self.assertEqual(params['QueryStartDateTime'], now_timestamp)
+        self.assertEqual(params['QueryStartDateTime'], transform_date(now))
         self.assertEqual(params['ResponseGroup'], 'Detailed')
         self.assertEqual(params['SellerSkus.member.1'], 'thing1')
         self.assertEqual(params['SellerSkus.member.2'], 'thing2')
diff --git a/tests/request_methods/test_orders.py b/tests/request_methods/test_orders.py
index 1b2a72b0..e3707f50 100644
--- a/tests/request_methods/test_orders.py
+++ b/tests/request_methods/test_orders.py
@@ -4,7 +4,7 @@
 import datetime
 import unittest
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date
 
 
 class OrdersTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -12,6 +12,7 @@ class OrdersTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Orders.
     """
     # TODO: Add remaining methods for Orders
+
     def setUp(self):
         self.api = mws.Orders(
             self.CREDENTIAL_ACCESS,
@@ -26,13 +27,9 @@ def test_list_orders(self):
         ListOrders operation.
         """
         created_after = datetime.datetime.utcnow()
-        created_after_stamp = created_after.isoformat()
         created_before = datetime.datetime.utcnow() + datetime.timedelta(hours=1)
-        created_before_stamp = created_before.isoformat()
         last_updated_after = datetime.datetime.utcnow() + datetime.timedelta(hours=2)
-        last_updated_after_stamp = last_updated_after.isoformat()
         last_updated_before = datetime.datetime.utcnow() + datetime.timedelta(hours=3)
-        last_updated_before_stamp = last_updated_before.isoformat()
         max_results = 83
         marketplace_ids = [
             'DV1t7ZOrjM',
@@ -72,13 +69,13 @@ def test_list_orders(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListOrders')
-        self.assertEqual(params['CreatedAfter'], created_after_stamp)
-        self.assertEqual(params['CreatedBefore'], created_before_stamp)
-        self.assertEqual(params['LastUpdatedAfter'], last_updated_after_stamp)
-        self.assertEqual(params['LastUpdatedBefore'], last_updated_before_stamp)
-        self.assertEqual(params['BuyerEmail'], buyer_email)
+        self.assertEqual(params['CreatedAfter'], transform_date(created_after))
+        self.assertEqual(params['CreatedBefore'], transform_date(created_before))
+        self.assertEqual(params['LastUpdatedAfter'], transform_date(last_updated_after))
+        self.assertEqual(params['LastUpdatedBefore'], transform_date(last_updated_before))
+        self.assertEqual(params['BuyerEmail'], 'dudley.do.right%40example.com')
         self.assertEqual(params['SellerOrderId'], seller_order_id)
-        self.assertEqual(params['MaxResultsPerPage'], max_results)
+        self.assertEqual(params['MaxResultsPerPage'], str(max_results))
         self.assertEqual(params['OrderStatus.Status.1'], order_statuses[0])
         self.assertEqual(params['OrderStatus.Status.2'], order_statuses[1])
         self.assertEqual(params['MarketplaceId.Id.1'], marketplace_ids[0])
diff --git a/tests/request_methods/test_outboundshipments.py b/tests/request_methods/test_outboundshipments.py
index d7b4757b..9859fc50 100644
--- a/tests/request_methods/test_outboundshipments.py
+++ b/tests/request_methods/test_outboundshipments.py
@@ -11,6 +11,7 @@ class OutboundShipmentsTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for OutboundShipments.
     """
     # TODO: Add remaining methods for OutboundShipments
+
     def setUp(self):
         self.api = mws.OutboundShipments(
             self.CREDENTIAL_ACCESS,
diff --git a/tests/request_methods/test_products.py b/tests/request_methods/test_products.py
index 57d55730..1d924adb 100644
--- a/tests/request_methods/test_products.py
+++ b/tests/request_methods/test_products.py
@@ -3,7 +3,7 @@
 """
 import unittest
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_bool, transform_string
 
 
 class ProductsTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -11,6 +11,7 @@ class ProductsTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Products.
     """
     # TODO: Add remaining methods for Products
+
     def setUp(self):
         self.api = mws.Products(
             self.CREDENTIAL_ACCESS,
@@ -34,8 +35,8 @@ def test_list_matching_products(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListMatchingProducts')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['Query'], query)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['Query'], transform_string(query))
         self.assertEqual(params['QueryContextId'], context_id)
 
     def test_get_matching_product(self):
@@ -53,7 +54,7 @@ def test_get_matching_product(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetMatchingProduct')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['ASINList.ASIN.1'], asins[0])
         self.assertEqual(params['ASINList.ASIN.2'], asins[1])
 
@@ -74,7 +75,7 @@ def test_get_matching_product_for_id(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetMatchingProductForId')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['IdType'], type_)
         self.assertEqual(params['IdList.Id.1'], ids[0])
         self.assertEqual(params['IdList.Id.2'], ids[1])
@@ -94,7 +95,7 @@ def test_get_competitive_pricing_for_sku(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetCompetitivePricingForSKU')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['SellerSKUList.SellerSKU.1'], skus[0])
         self.assertEqual(params['SellerSKUList.SellerSKU.2'], skus[1])
 
@@ -113,7 +114,7 @@ def test_get_competitive_pricing_for_asin(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetCompetitivePricingForASIN')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['ASINList.ASIN.1'], asins[0])
         self.assertEqual(params['ASINList.ASIN.2'], asins[1])
 
@@ -137,11 +138,11 @@ def test_get_lowest_offer_listings_for_sku(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetLowestOfferListingsForSKU')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['ItemCondition'], condition)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['ItemCondition'], transform_string(condition))
         # TODO when this fails later after "clean" implemented, test against str conversion instead
         # (use commented `exclude_me_str` above)
-        self.assertEqual(params['ExcludeMe'], exclude_me)
+        self.assertEqual(params['ExcludeMe'], 'true')
         self.assertEqual(params['SellerSKUList.SellerSKU.1'], skus[0])
         self.assertEqual(params['SellerSKUList.SellerSKU.2'], skus[1])
 
@@ -165,11 +166,11 @@ def test_get_lowest_offer_listings_for_asin(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetLowestOfferListingsForASIN')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['ItemCondition'], condition)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['ItemCondition'], transform_string(condition))
         # TODO when this fails later after "clean" implemented, test against str conversion instead
         # (use commented `exclude_me_str` above)
-        self.assertEqual(params['ExcludeMe'], exclude_me)
+        self.assertEqual(params['ExcludeMe'], transform_bool(exclude_me))
         self.assertEqual(params['ASINList.ASIN.1'], asins[0])
         self.assertEqual(params['ASINList.ASIN.2'], asins[1])
 
@@ -190,11 +191,11 @@ def test_get_lowest_priced_offers_for_sku(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetLowestPricedOffersForSKU')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['ItemCondition'], condition)
         # TODO when this fails later after "clean" implemented, test against str conversion instead
         # (use commented `exclude_me_str` above)
-        self.assertEqual(params['ExcludeMe'], exclude_me)
+        self.assertEqual(params['ExcludeMe'], transform_bool(exclude_me))
         self.assertEqual(params['SellerSKU'], sku)
 
     def test_get_lowest_priced_offers_for_asin(self):
@@ -214,11 +215,11 @@ def test_get_lowest_priced_offers_for_asin(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetLowestPricedOffersForASIN')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['ItemCondition'], condition)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['ItemCondition'], transform_string(condition))
         # TODO when this fails later after "clean" implemented, test against str conversion instead
         # (use commented `exclude_me_str` above)
-        self.assertEqual(params['ExcludeMe'], exclude_me)
+        self.assertEqual(params['ExcludeMe'], 'true')
         self.assertEqual(params['ASIN'], asin)
 
     # def test_get_my_fees_estimate(self):
@@ -244,8 +245,8 @@ def test_get_my_price_for_sku(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetMyPriceForSKU')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['ItemCondition'], condition)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['ItemCondition'], transform_string(condition))
         self.assertEqual(params['SellerSKUList.SellerSKU.1'], skus[0])
         self.assertEqual(params['SellerSKUList.SellerSKU.2'], skus[1])
 
@@ -266,8 +267,8 @@ def test_get_my_price_for_asin(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetMyPriceForASIN')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['ItemCondition'], condition)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
+        self.assertEqual(params['ItemCondition'], transform_string(condition))
         self.assertEqual(params['ASINList.ASIN.1'], asins[0])
         self.assertEqual(params['ASINList.ASIN.2'], asins[1])
 
@@ -283,7 +284,7 @@ def test_get_product_categories_for_sku(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetProductCategoriesForSKU')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['SellerSKU'], sku)
 
     def test_get_product_categories_for_asin(self):
@@ -298,5 +299,5 @@ def test_get_product_categories_for_asin(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetProductCategoriesForASIN')
-        self.assertEqual(params['MarketplaceId'], marketplace_id)
+        self.assertEqual(params['MarketplaceId'], transform_string(marketplace_id))
         self.assertEqual(params['ASIN'], asin)
diff --git a/tests/request_methods/test_recommendations.py b/tests/request_methods/test_recommendations.py
index 3a049fc1..cfbb6acd 100644
--- a/tests/request_methods/test_recommendations.py
+++ b/tests/request_methods/test_recommendations.py
@@ -3,7 +3,7 @@
 """
 import unittest
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_string
 
 
 class RecommendationsTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -11,6 +11,7 @@ class RecommendationsTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Recommendations.
     """
     # TODO: Add remaining methods for Recommendations
+
     def setUp(self):
         self.api = mws.Recommendations(
             self.CREDENTIAL_ACCESS,
@@ -43,7 +44,8 @@ def test_list_recommendations(self):
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'ListRecommendations')
         self.assertEqual(params['MarketplaceId'], marketplace_id)
-        self.assertEqual(params['RecommendationCategory'], recommendation_category)
+        self.assertEqual(params['RecommendationCategory'],
+                         transform_string(recommendation_category))
 
     def test_list_recommendations_by_next_token(self):
         """
diff --git a/tests/request_methods/test_reports.py b/tests/request_methods/test_reports.py
index f64e68b2..1c556548 100644
--- a/tests/request_methods/test_reports.py
+++ b/tests/request_methods/test_reports.py
@@ -4,7 +4,7 @@
 import datetime
 import unittest
 import mws
-from .utils import CommonRequestTestTools
+from .utils import CommonRequestTestTools, transform_date, transform_bool
 
 
 class ReportsTestCase(unittest.TestCase, CommonRequestTestTools):
@@ -12,6 +12,7 @@ class ReportsTestCase(unittest.TestCase, CommonRequestTestTools):
     Test cases for Reports.
     """
     # TODO: Add remaining methods for Reports
+
     def setUp(self):
         self.api = mws.Reports(
             self.CREDENTIAL_ACCESS,
@@ -26,8 +27,8 @@ def test_request_report(self):
         RequestReport operation.
         """
         report_type = '_GET_FLAT_FILE_OPEN_LISTINGS_DATA_'
-        start_date = datetime.datetime.utcnow()
-        end_date = datetime.datetime.utcnow() + datetime.timedelta(hours=1)
+        start_date = datetime.datetime(2018, 4, 30, 22, 59, 59)
+        end_date = datetime.datetime(2018, 4, 30, 23, 59, 59)
         marketplace_ids = [
             'iQzBCmf1y3',
             'wH9q0CiEMp',
@@ -38,14 +39,35 @@ def test_request_report(self):
             end_date=end_date,
             marketplace_ids=marketplace_ids,
         )
+
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'RequestReport')
         self.assertEqual(params['ReportType'], report_type)
-        self.assertEqual(params['StartDate'], start_date.isoformat())
-        self.assertEqual(params['EndDate'], end_date.isoformat())
+        self.assertEqual(params['StartDate'], '2018-04-30T22%3A59%3A59')
+        self.assertEqual(params['EndDate'], '2018-04-30T23%3A59%3A59')
         self.assertEqual(params['MarketplaceIdList.Id.1'], marketplace_ids[0])
         self.assertEqual(params['MarketplaceIdList.Id.2'], marketplace_ids[1])
 
+    def test_parameter_error(self):
+            """
+            RequestReport wrong parameter
+            """
+            # list will throw error
+            report_type = ['_GET_FLAT_FILE_OPEN_LISTINGS_DATA_']
+            start_date = datetime.datetime(2018, 4, 30, 22, 59, 59)
+            end_date = datetime.datetime(2018, 4, 30, 23, 59, 59)
+            marketplace_ids = [
+                'iQzBCmf1y3',
+                'wH9q0CiEMp',
+            ]
+            with self.assertRaises(mws.MWSError):
+                self.api.request_report(
+                    report_type=report_type,
+                    start_date=start_date,
+                    end_date=end_date,
+                    marketplace_ids=marketplace_ids,
+                )
+
     def test_get_report_request_list(self):
         """
         GetReportRequestList operation.
@@ -75,9 +97,9 @@ def test_get_report_request_list(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetReportRequestList')
-        self.assertEqual(params['MaxCount'], max_count)
-        self.assertEqual(params['RequestedFromDate'], from_date.isoformat())
-        self.assertEqual(params['RequestedToDate'], to_date.isoformat())
+        self.assertEqual(params['MaxCount'], str(max_count))
+        self.assertEqual(params['RequestedFromDate'], transform_date(from_date))
+        self.assertEqual(params['RequestedToDate'], transform_date(to_date))
         self.assertEqual(params['ReportRequestIdList.Id.1'], request_ids[0])
         self.assertEqual(params['ReportRequestIdList.Id.2'], request_ids[1])
         self.assertEqual(params['ReportTypeList.Type.1'], report_types[0])
@@ -127,8 +149,8 @@ def test_get_report_request_count(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetReportRequestCount')
-        self.assertEqual(params['RequestedFromDate'], from_date.isoformat())
-        self.assertEqual(params['RequestedToDate'], to_date.isoformat())
+        self.assertEqual(params['RequestedFromDate'], transform_date(from_date))
+        self.assertEqual(params['RequestedToDate'], transform_date(to_date))
         self.assertEqual(params['ReportTypeList.Type.1'], report_types[0])
         self.assertEqual(params['ReportTypeList.Type.2'], report_types[1])
         self.assertEqual(params['ReportProcessingStatusList.Status.1'], processing_statuses[0])
@@ -160,10 +182,10 @@ def test_get_report_list(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetReportList')
-        self.assertEqual(params['Acknowledged'], acknowledged)
-        self.assertEqual(params['AvailableFromDate'], from_date.isoformat())
-        self.assertEqual(params['AvailableToDate'], to_date.isoformat())
-        self.assertEqual(params['MaxCount'], max_count)
+        self.assertEqual(params['Acknowledged'], transform_bool(acknowledged))
+        self.assertEqual(params['AvailableFromDate'], transform_date(from_date))
+        self.assertEqual(params['AvailableToDate'], transform_date(to_date))
+        self.assertEqual(params['MaxCount'], str(max_count))
         self.assertEqual(params['ReportRequestIdList.Id.1'], request_ids[0])
         self.assertEqual(params['ReportRequestIdList.Id.2'], request_ids[1])
         self.assertEqual(params['ReportTypeList.Type.1'], report_types[0])
@@ -208,9 +230,9 @@ def test_get_report_count(self):
         )
         self.assert_common_params(params)
         self.assertEqual(params['Action'], 'GetReportCount')
-        self.assertEqual(params['Acknowledged'], acknowledged)
-        self.assertEqual(params['AvailableFromDate'], from_date.isoformat())
-        self.assertEqual(params['AvailableToDate'], to_date.isoformat())
+        self.assertEqual(params['Acknowledged'], transform_bool(acknowledged))
+        self.assertEqual(params['AvailableFromDate'], transform_date(from_date))
+        self.assertEqual(params['AvailableToDate'], transform_date(to_date))
         self.assertEqual(params['ReportTypeList.Type.1'], report_types[0])
         self.assertEqual(params['ReportTypeList.Type.2'], report_types[1])
 
diff --git a/tests/request_methods/utils.py b/tests/request_methods/utils.py
index 16139db1..74e45583 100644
--- a/tests/request_methods/utils.py
+++ b/tests/request_methods/utils.py
@@ -3,6 +3,11 @@
 """
 import datetime
 
+try:
+    from urllib.parse import quote
+except ImportError:
+    from urllib import quote
+
 
 class CommonRequestTestTools(object):
     CREDENTIAL_ACCESS = 'cred_access'
@@ -22,13 +27,27 @@ def assert_common_params(self, params):
         # If test fails here, check that method.
         self.assertEqual(params['SignatureMethod'], 'HmacSHA256')
         self.assertEqual(params['SignatureVersion'], '2')
-        isoformat_str = "%Y-%m-%dT%H:%M:%S"
+        isoformat_str = "%Y-%m-%dT%H%%3A%M%%3A%S"
         try:
             datetime.datetime.strptime(params['Timestamp'], isoformat_str)
         except ValueError:
-            self.fail("Timestamp expected an ISO-8601 datetime string with format [YYYY-MM-DDTHH:MM:SS].")
+            self.fail(
+                "Timestamp expected an ISO-8601 datetime string url encoded"
+                " with format [YYYY-MM-DDTHH%3AMM%3ASS].")
 
     def test_service_status(self):
         response = self.api.get_service_status()
         # Only key we care about here is GetServiceStatus
         self.assertEqual(response['Action'], 'GetServiceStatus')
+
+
+def transform_string(s):
+    return quote(s, safe='-_.~')
+
+
+def transform_bool(b):
+    return str(b).lower()
+
+
+def transform_date(date):
+    return quote(date.isoformat(), safe='-_.~')
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 6b716da3..0f181dc3 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -11,7 +11,7 @@ def test_calc_request_description(access_key, account_id):
         'AWSAccessKeyId': access_key,
         'Markets': account_id,
         'SignatureVersion': '2',
-        'Timestamp': '2017-08-12T19:40:35Z',
+        'Timestamp': '2017-08-12T19%3A40%3A35Z',
         'Version': '2017-01-01',
         'SignatureMethod': 'HmacSHA256',
     })