diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index e77de34d..15d76e60 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -9,6 +9,14 @@ on:
   schedule:
     - cron: "0 6 * * 1"
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
diff --git a/.github/workflows/governance.yml b/.github/workflows/governance.yml
index 76bd1a0e..4bb50e9a 100644
--- a/.github/workflows/governance.yml
+++ b/.github/workflows/governance.yml
@@ -18,6 +18,14 @@ on:
   pull_request:
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
diff --git a/.github/workflows/scorecard-enforcer.yml b/.github/workflows/scorecard-enforcer.yml
index e89e8837..56285543 100644
--- a/.github/workflows/scorecard-enforcer.yml
+++ b/.github/workflows/scorecard-enforcer.yml
@@ -9,6 +9,14 @@ on:
     - cron: "0 6 * * 1" # Weekly on Monday
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
diff --git a/.github/workflows/scorecard.yml b/.github/workflows/scorecard.yml
index 795fbc10..afc98e3d 100644
--- a/.github/workflows/scorecard.yml
+++ b/.github/workflows/scorecard.yml
@@ -7,6 +7,14 @@ on:
     - cron: "0 4 * * *"
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
diff --git a/.github/workflows/secret-scanner.yml b/.github/workflows/secret-scanner.yml
index 755e0530..9bb4f7f9 100644
--- a/.github/workflows/secret-scanner.yml
+++ b/.github/workflows/secret-scanner.yml
@@ -7,6 +7,14 @@ on:
   push:
     branches: [main]
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -70,4 +78,4 @@ jobs:
           if [ $found -eq 1 ]; then
             echo "::error::Potential hardcoded secrets detected. Use environment variables instead."
             exit 1
-          fi
\ No newline at end of file
+          fi