diff --git a/.changeset/modern-trees-add.md b/.changeset/modern-trees-add.md
new file mode 100644
index 0000000000..64b36c3adb
--- /dev/null
+++ b/.changeset/modern-trees-add.md
@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-techdocs': minor
+'@backstage/plugin-catalog': minor
+---
+
+This change allows a new annotation of `backstage.io/techdocs-external-ref` this ref allows you to reference another entity for its TechDocs. This allows you have a single TechDoc for all items in a system, for example you might have a frontend and a backend in the same repo. This would allow you to have TechDocs build under a `System` entity while referencing the system e.g.: `backstage.io/techdocs-external-ref: system:default/example` that will show the systems docs in both the TechDocs button and the TechDocs tab without needing to do duplicate builds and filling the TechDocs page with garbage.
diff --git a/docs/features/techdocs/how-to-guides.md b/docs/features/techdocs/how-to-guides.md
index ab554db3bd..0ab89ed9b6 100644
--- a/docs/features/techdocs/how-to-guides.md
+++ b/docs/features/techdocs/how-to-guides.md
@@ -678,3 +678,32 @@ entity. If the value of this annotation is `'local'`, the TechDocs backend will
 and publish the documentation for them. If the value of the `company.com/techdocs-builder`
 annotation is anything other than `'local'`, the user is responsible for publishing
 documentation to the appropriate location in the TechDocs external storage.
+
+## Reference another components TechDocs
+
+In systems where you might have multiple entities for example a System with a Website and an API, when served from a Monorepo you might want to keep the TechDocs in one location in the repository.
+
+In this case you can add the `backstage.io/techdocs-external-ref` annotation and point to the owners `entityRef` and use its TechDocs. This allows the Subcomponents to read the parents docs, filling the TechDocs link on the `AboutCard` element and the Techdocs tab
+
+```yaml
+apiVersion: backstage.io/v1alpha1
+kind: System
+metadata:
+  name: example
+  namespace: default
+  title: Example
+  description: This is the parent entity
+  annotations:
+    backstage.io/techdocs-ref: dir:.
+
+---
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: example-platfrom
+  title: Example Application Platform
+  namespace: default
+  description: This is the child entity
+  annotations:
+    backstage.io/techdocs-external-ref: system:default/example
+```