diff --git a/ad_api/api/billing.py b/ad_api/api/billing.py
index 55ac914..c07cfbe 100644
--- a/ad_api/api/billing.py
+++ b/ad_api/api/billing.py
@@ -56,4 +56,43 @@ def list_billing_notifications(self, **kwargs) -> ApiResponse:
         headers = {'Content-Type': request_contentType, 'Accept': accept_contentType}
 
         body = Utils.convert_body(kwargs.pop('body'))
-        return self._request(kwargs.pop('path'), data=body, params=kwargs, headers=headers)
\ No newline at end of file
+        return self._request(kwargs.pop('path'), data=body, params=kwargs, headers=headers)
+
+
+
+    @sp_endpoint('/billing/paymentMethods/list', method='POST')
+    def get_customer_payment_methods(self, **kwargs) -> ApiResponse:
+        r"""
+        """
+        accept_contentType = 'application/vnd.paymentmethods.v1+json'
+        headers = {'Accept': accept_contentType}
+        return self._request(kwargs.pop('path'), params=kwargs, headers=headers)
+
+
+
+    @sp_endpoint('/billing/invoices/pay', method='POST')
+    def pay_invoices(self, **kwargs) -> ApiResponse:
+        r"""
+        """
+        accept_contentType = 'application/vnd.invoices.v1+json'
+        headers = {'Accept': accept_contentType}
+        body = Utils.convert_body(kwargs.pop('body'), False)
+        return self._request(kwargs.pop('path'), data=body, params=kwargs, headers=headers)
+
+    @sp_endpoint('/billing/paymentAgreements/list', method='POST')
+    def get_payment_agreements(self, **kwargs) -> ApiResponse:
+        r"""
+        """
+        accept_contentType = 'application/vnd.paymentagreements.v1+json'
+        headers = {'Accept': accept_contentType}
+        return self._request(kwargs.pop('path'), params=kwargs, headers=headers)
+
+
+    @sp_endpoint('/billing/paymentAgreements', method='POST')
+    def create_payment_agreements(self, **kwargs) -> ApiResponse:
+        r"""
+        """
+        accept_contentType = 'application/vnd.paymentagreements.v1+json'
+        headers = {'Accept': accept_contentType}
+        body = Utils.convert_body(kwargs.pop('body'), False)
+        return self._request(kwargs.pop('path'), data=body, params=kwargs, headers=headers)
diff --git a/ad_api/api/sb/negative_keywords.py b/ad_api/api/sb/negative_keywords.py
index 5dff4a7..3c82e29 100644
--- a/ad_api/api/sb/negative_keywords.py
+++ b/ad_api/api/sb/negative_keywords.py
@@ -1,4 +1,4 @@
-from ad_api.base import Client, sp_endpoint, fill_query_params, ApiResponse
+from ad_api.base import Client, sp_endpoint, fill_query_params, ApiResponse, Utils
 
 class NegativeKeywords(Client):
     """
@@ -47,7 +47,8 @@ def edit_negative_keywords(self, **kwargs) -> ApiResponse:
             ApiResponse
 
         """
-        return self._request(kwargs.pop('path'), data=kwargs.pop('body'), params=kwargs)
+        body = Utils.convert_body(kwargs.pop('body'), wrap=False)
+        return self._request(kwargs.pop('path'), data=body, params=kwargs)
 
     @sp_endpoint('/sb/negativeKeywords', method='POST')
     def create_negative_keywords(self, **kwargs) -> ApiResponse:
@@ -73,7 +74,8 @@ def create_negative_keywords(self, **kwargs) -> ApiResponse:
             ApiResponse
 
         """
-        return self._request(kwargs.pop('path'), data=kwargs.pop('body'), params=kwargs)
+        body = Utils.convert_body(kwargs.pop('body'), wrap=False)
+        return self._request(kwargs.pop('path'), data=body, params=kwargs)
 
     @sp_endpoint('/sb/negativeKeywords/{}', method='GET')
     def get_negative_keyword(self, keywordId, **kwargs) -> ApiResponse:
diff --git a/ad_api/version.py b/ad_api/version.py
index 7dd6fda..2468911 100644
--- a/ad_api/version.py
+++ b/ad_api/version.py
@@ -1 +1 @@
-__version__ = "0.5.1"
\ No newline at end of file
+__version__ = "0.5.2"
\ No newline at end of file
diff --git a/setup.cfg b/setup.cfg
index 9750389..c301a16 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = python-amazon-ad-api
-version = 0.5.1
+version = 0.5.2
 author = Daniel Alvaro
 author_email = denisneuf@hotmail.com
 description = Python wrapper for the Amazon Advertising API
diff --git a/setup.py b/setup.py
index 63cf0f9..ed640bc 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 
 setup(
     name='python-amazon-ad-api',
-    version='0.5.1',
+    version='0.5.2',
     install_requires=[
         "requests>=2.27.1,<2.32.0",
         "six~=1.16.0",