diff --git a/README.md b/README.md
index 2eda77e..17f3094 100644
--- a/README.md
+++ b/README.md
@@ -528,6 +528,7 @@ So if you’re not going to manage your AWS configurations manually, what should
 	-	To label lifecycles, such as temporary resources or one that should be deprovisioned in the future
 	-	To distinguish production-critical infrastructure (e.g. serving systems vs backend pipelines)
 	-	To distinguish resources with special security or compliance requirements
+	-	To (once enabled) [allocate cost](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/cost-alloc-tags.html). Note that cost allocation tags only apply on a forward-looking basis; you can't retroactively apply them to items already billed.
 	-	For many years, there was a notorious 10 tag limit per resource, which could not be raised and caused many companies significant pain. As of 2016, this was [raised](https://aws.amazon.com/blogs/security/now-organize-your-aws-resources-by-using-up-to-50-tags-per-resource/) to 50 tags per resource.
 	-	🔹In 2017, AWS introduced the ability to [enforce tagging](https://aws.amazon.com/blogs/aws/new-tag-ec2-instances-ebs-volumes-on-creation/) on instance and volume creation, deprecating portions of third party tools such as [Cloud Custodian](https://github.com/capitalone/cloud-custodian).