diff --git a/.github/scripts/app_store_connect_release.rb b/.github/scripts/app_store_connect_release.rb
index 6663e2ed..3261057e 100644
--- a/.github/scripts/app_store_connect_release.rb
+++ b/.github/scripts/app_store_connect_release.rb
@@ -269,10 +269,19 @@ def distribute_testflight(build)
         raise AppStoreConnectError, "TestFlight build cannot be distributed: #{state}"
       end
     end
-    @client.post("/v1/builds/#{build_id}/relationships/betaGroups", data: selected.map do |group|
-      { type: "betaGroups", id: group.fetch("id") }
-    end)
-    puts "Assigned #{@options[:platform]} build #{@options[:build_number]} to #{@options[:testflight_groups].join(', ')}"
+    selected.each do |group|
+      # Automatic internal groups already receive every build; Apple rejects
+      # manually assigning them. The group endpoint supports manual groups.
+      if group.dig("attributes", "isInternalGroup") && group.dig("attributes", "hasAccessToAllBuilds")
+        puts "#{group.dig('attributes', 'name')} already has automatic access to all builds"
+        next
+      end
+
+      @client.post("/v1/betaGroups/#{group.fetch('id')}/relationships/builds", data: [
+        { type: "builds", id: build_id }
+      ])
+    end
+    puts "Distributed #{@options[:platform]} build #{@options[:build_number]} to #{@options[:testflight_groups].join(', ')}"
   end
 
   def find_or_create_version
diff --git a/.github/scripts/test/app_store_connect_release_test.rb b/.github/scripts/test/app_store_connect_release_test.rb
index 1b9da4b2..e4f38fd2 100644
--- a/.github/scripts/test/app_store_connect_release_test.rb
+++ b/.github/scripts/test/app_store_connect_release_test.rb
@@ -120,7 +120,7 @@ def patch(path, body)
 
   def beta_groups
     [
-      { 'id' => 'internal', 'attributes' => { 'name' => 'Internal Testing', 'isInternalGroup' => true } },
+      { 'id' => 'internal', 'attributes' => { 'name' => 'Internal Testing', 'isInternalGroup' => true, 'hasAccessToAllBuilds' => true } },
       { 'id' => 'external', 'attributes' => { 'name' => 'External Testing', 'isInternalGroup' => false } }
     ]
   end
@@ -131,11 +131,34 @@ def test_testflight_uses_only_existing_groups_and_beta_review
       release(client, process_only: false, testflight_groups: ['Internal Testing', 'External Testing']).run
     end
     assert client.mutations.any? { |_, path, _| path == '/v1/betaAppReviewSubmissions' }
-    assert_equal '/v1/builds/uploaded-build/relationships/betaGroups', client.mutations.last[1]
-    assert_equal %w[internal external], client.mutations.last[2][:data].map { |group| group[:id] }
+    assignments = client.mutations.select { |_, path, _| path.start_with?('/v1/betaGroups/') }
+    assert_equal [[:post, '/v1/betaGroups/external/relationships/builds',
+                   { data: [{ type: 'builds', id: 'uploaded-build' }] }]], assignments
+    refute client.mutations.any? { |_, path, _| path.end_with?('/relationships/betaGroups') }
     refute client.mutations.any? { |_, path, _| path.include?('appStoreVersions') || path.include?('reviewSubmissions') }
   end
 
+  def test_automatic_internal_group_needs_no_assignment_or_beta_review
+    client = BetaClient.new([build], groups: beta_groups)
+    output, = capture_io do
+      release(client, process_only: false, testflight_groups: ['Internal Testing']).run
+    end
+    assert_match(/already has automatic access/, output)
+    refute client.mutations.any? { |_, path, _| path.include?('/relationships/') || path == '/v1/betaAppReviewSubmissions' }
+  end
+
+  def test_manual_internal_group_uses_group_build_relationship_without_beta_review
+    groups = beta_groups
+    groups.first['attributes']['hasAccessToAllBuilds'] = false
+    client = BetaClient.new([build], groups: groups)
+    capture_io do
+      release(client, process_only: false, testflight_groups: ['Internal Testing']).run
+    end
+    assert_equal [:post, '/v1/betaGroups/internal/relationships/builds',
+                  { data: [{ type: 'builds', id: 'uploaded-build' }] }], client.mutations.last
+    refute client.mutations.any? { |_, path, _| path == '/v1/betaAppReviewSubmissions' }
+  end
+
   def test_missing_testflight_group_fails_without_changing_apple
     client = BetaClient.new([build], groups: beta_groups)
     assert_raises(AppStoreConnectError) do
diff --git a/open_wearable/docs/apple-builds.md b/open_wearable/docs/apple-builds.md
index ede387ce..cb2a7463 100644
--- a/open_wearable/docs/apple-builds.md
+++ b/open_wearable/docs/apple-builds.md
@@ -33,6 +33,10 @@ Xcode Cloud main-branch distribution settings, including automatic notification
 when Apple makes an external build available. It does not submit a public App
 Store release.
 
+Internal groups with automatic access to all builds require no manual assignment.
+Other internal and external groups receive the build through their group build
+relationship; the build-to-groups endpoint rejects internal groups.
+
 The workflow can also be run manually against a chosen ref. Manual runs default
 to upload-only validation; enable `distribute` to send the build to those groups.