diff --git a/clients/sellingpartner-api-aa-csharp/README.md b/clients/sellingpartner-api-aa-csharp/README.md
index 7ae8977..ea3118b 100644
--- a/clients/sellingpartner-api-aa-csharp/README.md
+++ b/clients/sellingpartner-api-aa-csharp/README.md
@@ -61,7 +61,7 @@ AWSAuthenticationCredentials awsAuthenticationCredentials = new AWSAuthenticatio
 restRequest = new AWSSigV4Signer(awsAuthenticationCredentials)
     .Sign(restRequest, restClient.BaseUrl.Host);
 ```
-Note the IRestRequest reference is treated as **mutable** when signed.
+Note the IRestRequest reference is treated as **mutable** when signed. **AWSSigV4 Authentication is now optional**
 
 ## RateLimitConfiguration
 
@@ -77,6 +77,8 @@ RateLimitConfiguration rateLimitConfig = new RateLimitConfigurationOnRequests
             }; 
 
 ```
+## Version
+Selling Partner API Authentication/Authorization Library version 1.0
 
 ## Resources
 This package features Mustache templates designed for use with [swagger codegen](https://swagger.io/tools/swagger-codegen/). 
diff --git a/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/ApiClient.mustache b/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/ApiClient.mustache
index faad469..9a75056 100644
--- a/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/ApiClient.mustache
+++ b/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/ApiClient.mustache
@@ -49,7 +49,11 @@ namespace {{packageName}}.Client
         private void InterceptRequest(IRestRequest request)
         {
             lwaAuthorizationSigner.Sign(request);
-            awsSigV4Signer.Sign(request, RestClient.BaseUrl.Host);
+
+            if(awsSigV4Signer != null && RestClient.BaseUrl.Host.Contains("business-api.amazon.com"))
+            {
+                awsSigV4Signer.Sign(request, RestClient.BaseUrl.Host);
+            }
         }
 
         /// <summary>
@@ -74,7 +78,10 @@ namespace {{packageName}}.Client
             {{/netStandard}}
 
             lwaAuthorizationSigner = new LWAAuthorizationSigner(Configuration.AuthorizationCredentials);
-            awsSigV4Signer = new AWSSigV4Signer(Configuration.AuthenticationCredentials);
+            if(Configuration.AuthenticationCredentials != null)
+            {
+                awsSigV4Signer = new AWSSigV4Signer(Configuration.AuthenticationCredentials);
+            }
             rateLimitConfig = Configuration.RateLimitConfig;
             if(rateLimitConfig != null)
             { 
diff --git a/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/api.mustache b/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/api.mustache
index 32b375e..2075637 100644
--- a/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/api.mustache
+++ b/clients/sellingpartner-api-aa-csharp/src/Amazon.SellingPartnerAPIAA/resources/swagger-codegen/templates/api.mustache
@@ -464,18 +464,19 @@ namespace {{packageName}}.{{apiPackage}}
                     throw new NullReferenceException("LWAAuthoriztionCredentials not set");
                 }
 
-                if (awsAuthenticationCredentials == null)
-                {
-                    throw new NullReferenceException("AWSAuthenticationCredentials not set");
-                }
                 
                 {{packageName}}.Client.Configuration configuration = new {{packageName}}.Client.Configuration()
                 {
                     AuthorizationCredentials = lwaAuthorizationCredentials,
-                    AuthenticationCredentials = awsAuthenticationCredentials,
                     RateLimitConfig = rateLimitConfiguration
                 };
 
+    
+                if(awsAuthenticationCredentials != null)
+                {
+                    configuration.AuthenticationCredentials = awsAuthenticationCredentials;
+                }
+
                 // default HTTP connection timeout (in milliseconds)
                 configuration.Timeout = 100000;