diff --git a/poetry.lock b/poetry.lock
index 949fefcd2..6a1c8af62 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -2581,12 +2581,12 @@ setuptools = "*"
 
 [[package]]
 name = "notifications-python-client"
-version = "8.2.0"
+version = "9.0.0"
 description = "Python API client for GOV.UK Notify."
 optional = false
 python-versions = ">=3.7"
 files = [
-    {file = "notifications_python_client-8.2.0-py3-none-any.whl", hash = "sha256:8cd8bd01ae603a972a5413c430ca42b16f6481f37d98406c3e9b68c1c192f59e"},
+    {file = "notifications_python_client-9.0.0-py3-none-any.whl", hash = "sha256:664a5b5da2aa1a00efa8106bfa4855db04da95d79586e5edfb0411637d20d2d9"},
 ]
 
 [package.dependencies]
@@ -4732,4 +4732,4 @@ testing = ["big-O", "jaraco.functools", "jaraco.itertools", "more-itertools", "p
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.9,<3.12"
-content-hash = "fa9cb13d87e7b797c72dd6eb7a669289c28f76e1139ba719e99501793b3db28b"
+content-hash = "f6d89a19888ec8a666200c9c2552434c0f9efb49fb0d29d69b56707bae47315a"
diff --git a/pyproject.toml b/pyproject.toml
index 8996b23f6..205d5a8db 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,7 +39,7 @@ lxml = "==5.1.0"
 marshmallow = "==3.20.2"
 marshmallow-sqlalchemy = "==0.30.0"
 newrelic = "*"
-notifications-python-client = "==8.2.0"
+notifications-python-client = "==9.0.0"
 notifications-utils = {git = "https://github.com/GSA/notifications-utils.git"}
 oscrypto = "==1.3.0"
 packaging = "==23.2"