diff --git a/CHANGES.md b/CHANGES.md
index 28486b0b..efa33c29 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,14 @@
+# 4.0.0
+New features:
+- Added support for the Vonage Video API
+- Added error handling for APIs that return a 200 on failure
+
+Breaking changes:
+- Removed redundant intermediary `Error` class
+- Removed `Pay` action from NCCO builder
+- Removed `Redact` class and support for the Redact API as it's a dev preview product that's unsupported in the SDK
+- Removed `ApplicationV2` class. Use `Application` instead
+
 # 3.9.0
 - Dropped support for Python 3.7 as it's end-of-life and no longer receiving security updates
 
@@ -83,7 +94,7 @@ Enhancements:
 - Added Messages API v1.0 support. Messages API can now be used by calling the `client.messages.send_message()` method.
 
 # 2.7.0
-- Moved some client methods into their own classes: `account.py, application.py, 
+- Moved some client methods into their own classes: `account.py, application.py,
 message_search.py, number_insight.py, numbers.py, short_codes.py, ussd.py`
 - Deprecated the corresponding client methods. These will be removed in a major release that's coming soon.
 - Client now instantiates a class object for each API when it is created, e.g. `vonage.Client(key="mykey", secret="mysecret")`
diff --git a/src/vonage/client.py b/src/vonage/client.py
index a59c1a0f..ed086429 100644
--- a/src/vonage/client.py
+++ b/src/vonage/client.py
@@ -9,7 +9,6 @@
 from .number_insight import NumberInsight
 from .number_management import Numbers
 from .proactive_connect import ProactiveConnect
-from .redact import Redact
 from .short_codes import ShortCodes
 from .sms import Sms
 from .subaccounts import Subaccounts
diff --git a/src/vonage/errors.py b/src/vonage/errors.py
index 839b406e..938ae49c 100644
--- a/src/vonage/errors.py
+++ b/src/vonage/errors.py
@@ -36,11 +36,6 @@ class PricingTypeError(ClientError):
     """A pricing type was specified that is not allowed."""
 
 
-class RedactError(ClientError):
-
-    """Error related to the Redact class or Redact API."""
-
-
 class InvalidAuthenticationTypeError(ClientError):
     """An authentication method was specified that is not allowed."""
 
diff --git a/src/vonage/redact.py b/src/vonage/redact.py
deleted file mode 100644
index c1ec18f5..00000000
--- a/src/vonage/redact.py
+++ /dev/null
@@ -1,31 +0,0 @@
-from .errors import RedactError
-
-from deprecated import deprecated
-
-
-@deprecated(
-    version='3.0.0',
-    reason='This is a dev preview product and as such is not supported in this SDK.',
-)
-class Redact:
-    auth_type = 'header'
-
-    allowed_product_names = {'sms', 'voice', 'number-insight', 'verify', 'verify-sdk', 'messages'}
-
-    def __init__(self, client):
-        self._client = client
-
-    def redact_transaction(self, id: str, product: str, type=None):
-        self._check_allowed_product_name(product)
-        params = {"id": id, "product": product}
-        if type is not None:
-            params["type"] = type
-        return self._client.post(
-            self._client.api_host(), "/v1/redact/transaction", params, auth_type=Redact.auth_type
-        )
-
-    def _check_allowed_product_name(self, product):
-        if product not in self.allowed_product_names:
-            raise RedactError(
-                f'Invalid product name in redact request. Must be one of {self.allowed_product_names}.'
-            )
diff --git a/tests/conftest.py b/tests/conftest.py
index f388f7e2..cdfadbbd 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -97,11 +97,6 @@ def messages(client):
     return vonage.Messages(client)
 
 
-@pytest.fixture
-def redact(client):
-    return vonage.Redact(client)
-
-
 @pytest.fixture
 def application_v2(client):
     import vonage
diff --git a/tests/test_redact.py b/tests/test_redact.py
deleted file mode 100644
index 609e5d9e..00000000
--- a/tests/test_redact.py
+++ /dev/null
@@ -1,36 +0,0 @@
-from util import *
-from vonage.errors import RedactError
-
-
-def test_redact_invalid_product_name(redact):
-    with pytest.raises(RedactError):
-        redact.redact_transaction(id='not-a-real-id', product='fake-product')
-
-
-@responses.activate
-def test_redact_transaction(redact, dummy_data):
-    responses.add(
-        responses.POST,
-        "https://api.nexmo.com/v1/redact/transaction",
-        body=None,
-        status=204,
-    )
-
-    assert redact.redact_transaction(id="not-a-real-id", product="sms") is None
-    assert request_user_agent() == dummy_data.user_agent
-    assert request_content_type() == "application/json"
-
-
-@responses.activate
-def test_redact_transaction_with_type(redact, dummy_data):
-    responses.add(
-        responses.POST,
-        "https://api.nexmo.com/v1/redact/transaction",
-        body=None,
-        status=204,
-    )
-
-    assert redact.redact_transaction(id="some-id", product="sms", type="xyz") is None
-    assert request_user_agent() == dummy_data.user_agent
-    assert request_content_type() == "application/json"
-    assert b"xyz" in request_body()