diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72c91fcb7..40b0fb9ca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,9 +8,13 @@ The format is based on the [KeepAChangeLog] project.
 ## Unreleased
 
 ### Added
+- [#755] Kwargs for ClientCredential encoding and url_encoded. If `url_encoded` is `True` or is not 
+provided, the user-pass will be encoded using `quote_plus`. The `encoding` kwargs will be used to `encode` to bytes
+before encoding in base64. Then, the base64 will be decoded using this encoding also.
 - [#739] Better error message for providers which return HTTP Error 405 on userinfo
 - [#723] Add settings class to handle settings related to Client and Server
 
+[#755]: https://github.com/OpenIDC/pyoidc/pull/755/
 [#723]: https://github.com/OpenIDC/pyoidc/pull/723/
 [#739]: https://github.com/OpenIDC/pyoidc/pull/739/
 
diff --git a/src/oic/utils/authn/client.py b/src/oic/utils/authn/client.py
index 0ba9190c9..87494f615 100644
--- a/src/oic/utils/authn/client.py
+++ b/src/oic/utils/authn/client.py
@@ -90,13 +90,23 @@ class ClientSecretBasic(ClientAuthnMethod):
     Section 3.2.1 of OAuth 2.0 [RFC6749] using HTTP Basic authentication scheme.
     """
 
-    def construct(self, cis, request_args=None, http_args=None, **kwargs):
+    def construct(
+        self,
+        cis=None,
+        request_args=None,
+        http_args=None,
+        url_encoded: bool = True,
+        encoding: str = "utf-8",
+        **kwargs
+    ):
         """
         Create the request.
 
         :param cis: Request class instance
         :param request_args: Request arguments
         :param http_args: HTTP arguments
+        :param url_encoded: url encode the user-pass before converting to base64
+        :param encoding: encoding format of user-pass before converting to base64
         :return: dictionary of HTTP arguments
         """
         if http_args is None:
@@ -121,8 +131,11 @@ def construct(self, cis, request_args=None, http_args=None, **kwargs):
         if "headers" not in http_args:
             http_args["headers"] = {}
 
-        credentials = "{}:{}".format(quote_plus(user), quote_plus(passwd))
-        authz = base64.b64encode(credentials.encode("utf-8")).decode("utf-8")
+        if url_encoded:
+            user, passwd = quote_plus(user), quote_plus(passwd)
+
+        credentials = b":".join((user.encode(encoding), passwd.encode(encoding)))
+        authz = base64.b64encode(credentials).decode(encoding)
         http_args["headers"]["Authorization"] = "Basic {}".format(authz)
 
         try:
diff --git a/tests/test_client.py b/tests/test_client.py
index 295d7b0b6..6c26d5430 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -58,16 +58,40 @@ def client():
 
 
 class TestClientSecretBasic(object):
-    def test_construct(self, client):
-        cis = AccessTokenRequest(code="foo", redirect_uri="http://example.com")
+    @pytest.mark.parametrize(
+        "url_encoded, encoding",
+        ((False, "latin1"), (True, "latin1"), (None, None), (False, None)),
+    )
+    def test_construct(self, client, url_encoded, encoding):
 
+        cis = AccessTokenRequest(code="foo", redirect_uri="http://example.com")
         csb = ClientSecretBasic(client)
-        http_args = csb.construct(cis)
-        cred = "{}:{}".format(quote_plus("A"), quote_plus("boarding pass"))
+
+        user, passwd = "A", "boarding pass"
+        kwargs = {}
+        if url_encoded is None or url_encoded:
+            user, passwd = (
+                quote_plus(user),
+                quote_plus(passwd),
+            )
+
+        if url_encoded is not None:
+            kwargs.update({"url_encoded": url_encoded})
+
+        if encoding is None:
+            encoding = "utf-8"
+        else:
+            kwargs.update({"encoding": encoding})
+
+        http_args = csb.construct(cis, **kwargs)
+
+        user, passwd = user.encode(encoding), passwd.encode(encoding)
+
+        cred = b":".join((user, passwd))
         assert http_args == {
             "headers": {
                 "Authorization": "Basic {}".format(
-                    base64.b64encode(cred.encode("utf-8")).decode("utf-8")
+                    base64.b64encode(cred).decode(encoding)
                 )
             }
         }
diff --git a/tests/utils/test_authn_client.py b/tests/utils/test_authn_client.py
index 07f91ec9f..e8979398f 100644
--- a/tests/utils/test_authn_client.py
+++ b/tests/utils/test_authn_client.py
@@ -7,9 +7,9 @@
 from oic.utils.authn.client import get_client_id
 
 CDB = {
-    "number5": {"client_secret": "drickyoughurt"},
+    "number5": {"client_secret": "drickyoughurt*"},
     "token_client": {},
-    "expired": {"client_secret": "drickyoughurt", "client_secret_expires_at": 1},
+    "expired": {"client_secret": "drickyoughurt*", "client_secret_expires_at": 1},
     "secret_token": "token_client",
     "expired_token": "expired",
 }
@@ -45,11 +45,11 @@ def test_wrong_authn(self):
             get_client_id(self.cdb, AuthorizationRequest(), "mumbo jumbo")
 
     def test_basic_authn_client_ok(self):
-        authn = "Basic " + b64encode(b"number5:drickyoughurt").decode()
+        authn = "Basic " + b64encode(b"number5:drickyoughurt*").decode()
         assert get_client_id(self.cdb, AuthorizationRequest(), authn)
 
     def test_basic_authn_client_missing(self):
-        authn = "Basic " + b64encode(b"missing:drickyoughurt").decode()
+        authn = "Basic " + b64encode(b"missing:drickyoughurt*").decode()
         with pytest.raises(FailedAuthentication):
             get_client_id(self.cdb, AuthorizationRequest(), authn)
 
@@ -59,7 +59,7 @@ def test_basic_authn_client_wrongpass(self):
             get_client_id(self.cdb, AuthorizationRequest(), authn)
 
     def test_basic_authn_client_invalid(self):
-        authn = "Basic " + b64encode(b"expired:drickyoughurt").decode()
+        authn = "Basic " + b64encode(b"expired:drickyoughurt*").decode()
         with pytest.raises(FailedAuthentication):
             get_client_id(self.cdb, AuthorizationRequest(), authn)