diff --git a/CHANGELOG.md b/CHANGELOG.md
index e2f6fe6..cafa414 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,11 @@
 # CHANGELOG
 
-## Next major release
+## v9.0.0 (2023-12-06)
 
-- Removes `withCarbonOffset` parameter from `create`, `buy`, and `regenerateRates` functions of the Shipment service as EasyPost now offers Carbon Neutral shipments by default for free
-- Removes the undocumented `createAndBuy` function from the `Batch` service. The proper usage is to create a batch first and buy it separately
+See our [Upgrade Guide](UPGRADE_GUIDE.md#upgrading-from-8x-to-90) for more details.
+
+- Removes `with_carbon_offset` parameter from `create`, `buy`, and `regenerate_rates` functions of the Shipment service as EasyPost now offers Carbon Neutral shipments by default for free
+- Removes the undocumented `create_and_buy` function from the `Batch` service. The proper usage is to create a batch first and buy it separately
 - Removes the `beta_carrier_metadata` service as it is deprecated, please use the `carrier_metadata` GA service instead
 
 ## v8.2.1 (2023-10-30)
diff --git a/UPGRADE_GUIDE.md b/UPGRADE_GUIDE.md
index b759e37..f3fee66 100644
--- a/UPGRADE_GUIDE.md
+++ b/UPGRADE_GUIDE.md
@@ -2,12 +2,43 @@
 
 Use the following guide to assist in the upgrade process of the `easypost-python` library between major versions.
 
+- [Upgrading from 8.x to 9.0](#upgrading-from-8x-to-90)
 - [Upgrading from 7.x to 8.0](#upgrading-from-7x-to-80)
 - [Upgrading from 6.x to 7.0](#upgrading-from-6x-to-70)
 - [Upgrading from 5.x to 6.0](#upgrading-from-5x-to-60)
 
+## Upgrading from 8.x to 9.0
+
+### 9.0 High Impact Changes
+
+- [Carbon Offset Removed](#90-carbon-offset-removed)
+
+### 9.0 Low Impact Changes
+
+- [Create and Buy Batch Function Removed](#90-create-and-buy-batch-function-removed)
+
+### 9.0 Carbon Offset Removed
+
+*Likelihood of Impact: **High***
+
+EasyPost now offers Carbon Neutral shipments by default for free! Because of this, there is no longer a need to specify if you want to offset the carbon footprint of a shipment.
+
+The `with_carbon_offset` parameter of the `create`, `buy`, and `regenerate_rates` shipment functions has been removed.
+
+This is a high-impact change for those using `EndShippers`, as the signature for the `create` and `buy` shipment functions have changed. You will need to inspect these callsites to ensure that the EndShipper parameter is being passed in the correct place.
+
+### 9.0 Create and Buy Batch Function Removed
+
+*Likelihood of Impact: **Low***
+
+The `create_and_buy` batch endpoint has been deprecated, and the `create_and_buy` Batch service function has been removed.
+
+The correct procedure is to first create a batch and then purchase it with two separate API calls.
+
 ## Upgrading from 7.x to 8.0
 
+**NOTICE:** v8 is deprecated.
+
 ### 8.0 High Impact Changes
 
 - [Updated Dependencies](#80-updated-dependencies)
@@ -23,7 +54,7 @@ Use the following guide to assist in the upgrade process of the `easypost-python
 - [Beta Namespace Changed](#80-beta-namespace-changed)
 - [Changed Function Parameter Order and Return Types](#80-changed-function-parameter-order-and-return-types)
 
-## 8.0 Updated Dependencies
+### 8.0 Updated Dependencies
 
 Likelihood of Impact: High
 
@@ -35,7 +66,7 @@ easypost-python now requires Python 3.7 or greater.
 
 All dependencies had minor version bumps.
 
-## 8.0 EasyPostClient
+### 8.0 EasyPostClient
 
 Likelihood of Impact: High
 
@@ -110,13 +141,13 @@ Occurances of `scanform` are now `scan_form` and `Scanform` are now `ScanForm` t
 
 The `primary_or_secondary` parameter name for billing functions is now called `priority` to match the documentation and API.
 
-## 8.0 Beta Namespace Changed
+### 8.0 Beta Namespace Changed
 
 Likelihood of Impact: Low
 
 Previously, the beta namespace was found at `easypost.beta.x` where `x` is the name of your model. Now, the beta namespace is simply prepended to the name of your service: `client.beta_x`. for instance, you can call `client.beta_referral_customer.add_payment_method()`.
 
-## 8.0 Changed Function Parameter Order and Return Types
+### 8.0 Changed Function Parameter Order and Return Types
 
 Likelihood of Impact: Low
 
@@ -137,7 +168,7 @@ Functions that previously returned `True` now do not return anything as there is
 
 - [Removal of `get_rates()` Shipment Method](#70-removal-of-getrates-shipment-method)
 
-## 7.0 Updating Dependencies
+### 7.0 Updating Dependencies
 
 Likelihood of Impact: High
 
@@ -149,7 +180,7 @@ easypost-python now requires Python 3.6 or greater and has dropped support for P
 
 All dependencies had minor version bumps.
 
-## 7.0 `shipment.lowest_rate()` Now Expects a List
+### 7.0 `shipment.lowest_rate()` Now Expects a List
 
 Previously the `shipment.lowest_rate()` function expected a comma separated string list of filter criteria (carriers and services). These params have been corrected to expect an actual list object.
 
@@ -161,7 +192,7 @@ shipment.lowest_rate(carriers="USPS,FedEx", services="...")
 shipment.lowest_rate(carriers=["USPS", "FedEx"], services=["..."])
 ```
 
-## 7.0 Removal of `get_rates()` Shipment Method
+### 7.0 Removal of `get_rates()` Shipment Method
 
 Likelihood of Impact: Medium
 
@@ -176,7 +207,7 @@ The HTTP method used for the `get_rates` endpoint at the API level has changed f
 - [Updating Dependencies](#60-updating-dependencies)
 - [JSON Encoded Bodies](#60-json-encoded-bodies)
 
-## 6.0 Updating Dependencies
+### 6.0 Updating Dependencies
 
 Likelihood of Impact: High
 
@@ -184,7 +215,7 @@ Likelihood of Impact: High
 
 Bumps the `requests` library from v1 to v2.
 
-## 6.0 JSON Encoded Bodies
+### 6.0 JSON Encoded Bodies
 
 Likelihood of Impact: High
 
diff --git a/easypost/constant.py b/easypost/constant.py
index 957d692..7342fc4 100644
--- a/easypost/constant.py
+++ b/easypost/constant.py
@@ -1,6 +1,6 @@
 # flake8: noqa
 # Library version
-VERSION = "8.2.1"
+VERSION = "9.0.0"
 VERSION_INFO = [str(number) for number in VERSION.split(".")]
 
 # Client defaults
diff --git a/setup.py b/setup.py
index 99e02d0..b85ddb8 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 
 setup(
     name="easypost",
-    version="8.2.1",
+    version="9.0.0",
     description="EasyPost Shipping API Client Library for Python",
     author="EasyPost",
     author_email="support@easypost.com",