diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 9ba08aa..ecc3e80 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+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR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+# (no publish/mutation), so cancelling a superseded run is always safe.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 76bd1a0..4bb50e9 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+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR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+# (no publish/mutation), so cancelling a superseded run is always safe.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 0978fcb..7f43e53 100644
--- a/.github/workflows/scorecard-enforcer.yml
+++ b/.github/workflows/scorecard-enforcer.yml
@@ -13,6 +13,14 @@ 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+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR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+# (no publish/mutation), so cancelling a superseded run is always safe.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 6d4bc31..a64158f 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+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR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: read-all
 
 jobs:
diff --git a/.github/workflows/secret-scanner.yml b/.github/workflows/secret-scanner.yml
index 9b3cf86..f9e0da6 100644
--- a/.github/workflows/secret-scanner.yml
+++ b/.github/workflows/secret-scanner.yml
@@ -7,12 +7,20 @@ 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
 
 jobs:
-  trufflehog:
-    runs-on: ubuntu-latest
+  trufflehog:
+    runs-on: ubuntu-latest
     if: github.event_name == 'pull_request'
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -67,4 +75,4 @@ 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