diff --git a/checkout_sdk/oauth_access_token.py b/checkout_sdk/oauth_access_token.py
index d6bde6c5..efdea318 100644
--- a/checkout_sdk/oauth_access_token.py
+++ b/checkout_sdk/oauth_access_token.py
@@ -5,10 +5,12 @@
 
 class OAuthAccessToken:
     token: str
+    token_type: str
     expiration_date: datetime
 
-    def __init__(self, token: str, expiration_date: datetime):
+    def __init__(self, token: str, token_type: str, expiration_date: datetime):
         self.token = token
+        self.token_type = token_type
         self.expiration_date = expiration_date
 
     def is_valid(self):
diff --git a/checkout_sdk/oauth_credentials.py b/checkout_sdk/oauth_credentials.py
index 3cbd21f0..924c7a96 100644
--- a/checkout_sdk/oauth_credentials.py
+++ b/checkout_sdk/oauth_credentials.py
@@ -64,6 +64,8 @@ def get_access_token(self):
 
         data = {
             'grant_type': 'client_credentials',
+            'client_id': self.__client_id,
+            'client_secret': self.__client_secret,
             'scope': str.join(' ', self.__scopes)
         }
 
@@ -84,6 +86,7 @@ def get_access_token(self):
 
         response_json = response.json()
         self.__access_token = OAuthAccessToken(token=response_json['access_token'],
+                                               token_type=response_json['token_type'],
                                                expiration_date=datetime.now() + timedelta(
                                                    seconds=response_json['expires_in']))
         return self.__access_token
diff --git a/checkout_sdk/payments/contexts/contexts.py b/checkout_sdk/payments/contexts/contexts.py
index 06668bc0..63cbf8d9 100644
--- a/checkout_sdk/payments/contexts/contexts.py
+++ b/checkout_sdk/payments/contexts/contexts.py
@@ -55,7 +55,7 @@ class PaymentContextsProcessing:
     locale: str
     shipping_preference: ShippingPreference
     user_action: UserAction
-    partner_customer_risk_data: PaymentContextsPartnerCustomerRiskData
+    partner_customer_risk_data: list  # payment.contexts.PaymentContextsPartnerCustomerRiskData
     airline_data: list  # payment.contexts.PaymentContextsAirlineData
 
 
diff --git a/checkout_sdk/transfers/transfers.py b/checkout_sdk/transfers/transfers.py
index b79a0c81..884a265b 100644
--- a/checkout_sdk/transfers/transfers.py
+++ b/checkout_sdk/transfers/transfers.py
@@ -1,5 +1,7 @@
 from enum import Enum
 
+from checkout_sdk.common.enums import Currency
+
 
 class TransferType(str, Enum):
     COMMISSION = 'commission'
@@ -10,6 +12,7 @@ class TransferType(str, Enum):
 class TransferSource:
     id: str
     amount: int
+    currency: Currency
 
 
 class TransferDestination:
diff --git a/checkout_sdk/transfers/transfers_client.py b/checkout_sdk/transfers/transfers_client.py
index 9f93e313..c7eca474 100644
--- a/checkout_sdk/transfers/transfers_client.py
+++ b/checkout_sdk/transfers/transfers_client.py
@@ -16,7 +16,7 @@ def __init__(self, api_client: ApiClient,
                          configuration=configuration,
                          authorization_type=AuthorizationType.SECRET_KEY_OR_OAUTH)
 
-    def initiate_transfer_of_funds(self, create_transfer_request: CreateTransferRequest, idempotency_key: str = None):
+    def initiate_transfer_of_funds(self, create_transfer_request: CreateTransferRequest, idempotency_key: str):
         return self._api_client.post(self.__TRANSFERS_PATH, self._sdk_authorization(), create_transfer_request,
                                      idempotency_key)
 
diff --git a/tests/oauth_integration_test.py b/tests/oauth_integration_test.py
index 406ee5a1..75a6393d 100644
--- a/tests/oauth_integration_test.py
+++ b/tests/oauth_integration_test.py
@@ -14,7 +14,6 @@ def test_should_create_customer_with_oauth(oauth_api):
 
     customer_response = oauth_api.customers.create(customer_request)
     assert_response(customer_response, 'id')
-    return customer_response.id
 
 
 def test_should_fail_init_authorization_invalid_credentials():
diff --git a/tests/transfers/transfers_integration_test.py b/tests/transfers/transfers_integration_test.py
index c8422964..bd4b3fc3 100644
--- a/tests/transfers/transfers_integration_test.py
+++ b/tests/transfers/transfers_integration_test.py
@@ -1,5 +1,6 @@
 from __future__ import absolute_import
 
+from checkout_sdk.common.enums import Currency
 from checkout_sdk.exception import CheckoutApiException
 from checkout_sdk.transfers.transfers import CreateTransferRequest, TransferDestination, TransferSource, TransferType
 from tests.checkout_test_utils import assert_response, new_idempotency_key
@@ -9,6 +10,7 @@ def test_should_initiate_transfer_of_funds_idempotently(oauth_api):
     transfer_source = TransferSource()
     transfer_source.id = 'ent_kidtcgc3ge5unf4a5i6enhnr5m'
     transfer_source.amount = 100
+    transfer_source.currency = Currency.GBP
 
     transfer_destination = TransferDestination()
     transfer_destination.id = 'ent_w4jelhppmfiufdnatam37wrfc4'
@@ -23,6 +25,9 @@ def test_should_initiate_transfer_of_funds_idempotently(oauth_api):
     response = oauth_api.transfers.initiate_transfer_of_funds(transfer_request, idempotency_key)
     assert_response(response, 'id', 'status')
 
+    response2 = oauth_api.transfers.retrieve_a_transfer(response.id)
+    assert_response(response2, 'id', 'status', 'source', 'destination')
+
     try:
         oauth_api.transfers.initiate_transfer_of_funds(transfer_request, idempotency_key)
     except CheckoutApiException as err: