diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index ab5f115..e265845 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -502,11 +502,31 @@ class NetworkRepository @Inject constructor(
 1. **Create Release Branch**: `git checkout -b release/vX.Y.Z` (e.g., `release/v1.17`)
 2. **Update Version**: Increment `versionCode` and `versionName` in `app/build.gradle.kts`
 3. **Update Release Notes**: Add new release section in `project-resources/google-play/release-notes.md`
-4. **Build & Test**: Run `./gradlew clean assembleRelease bundleRelease`
+4. **Build & Test**: Run `./gradlew clean assembleRelease bundleRelease` **on your local machine**
 5. **Commit Changes**: Commit version bump and release notes on the release branch
 6. **Create PR**: Open pull request from release branch to `main`
 7. **Merge & Tag**: After PR approval, merge to `main` and create git tag `vX.Y.Z`
-8. **Upload to Play Store**: Upload AAB to Google Play Console
+8. **Upload to Play Store**: Upload the locally-built AAB (`app/release/app-release.aab`) to Google Play Console
+
+### ⚠️ Critical: App Bundle Signing
+
+**DO NOT upload release builds from GitHub Actions.** The release AAB must be built locally with the correct signing certificate registered in Google Play Console.
+
+**Why:** GitHub Actions builds and local builds use different keystores, which causes signing key mismatch errors when uploading to Google Play Console. See [Issue #438](https://github.com/hossain-khan/android-remote-notify/issues/438) for details.
+
+**Correct Process:**
+- Build release bundle locally on your machine with correct `local.properties` keystore path
+- Verify `local.properties` contains the correct keystore location and password
+- Upload the generated `app/release/app-release.aab` directly from your local machine
+- This ensures the bundle is signed with the certificate registered in Google Play
+
+**Troubleshooting Signing Errors:**
+If you encounter "Your App Bundle is signed with the wrong key" error:
+1. Verify the SHA1 fingerprint in Google Play Console
+2. Check that `local.properties` points to the correct keystore file
+3. Ensure the keystore password is correct
+4. Rebuild locally: `./gradlew clean bundleRelease`
+5. Re-upload the newly generated AAB
 
 ### Version Management
 - Update `versionCode` (increment by 1) and `versionName` in `app/build.gradle.kts`
@@ -519,7 +539,7 @@ class NetworkRepository @Inject constructor(
 - [ ] Update version code and name in `app/build.gradle.kts`
 - [ ] Update `release-notes.md` with new release section
 - [ ] Check `local.properties` for correct keystore path and password
-- [ ] Build release: `./gradlew clean assembleRelease bundleRelease`
+- [ ] Build release **locally**: `./gradlew clean assembleRelease bundleRelease`
 - [ ] Test release build locally
 - [ ] Run full test suite: `./gradlew test`
 - [ ] Check ProGuard/R8 obfuscation
@@ -528,17 +548,19 @@ class NetworkRepository @Inject constructor(
 - [ ] Create pull request to `main`
 - [ ] After merge, create git tag: `git tag -a vX.Y.Z -m "Release vX.Y.Z"`
 - [ ] Push tag: `git push origin vX.Y.Z`
-- [ ] Upload AAB to Firebase Test Lab
-- [ ] Upload AAB to Google Play Console
+- [ ] **Upload AAB to Google Play Console from your local machine** (not from GitHub Actions)
+  - Verify keystore SHA1 matches Google Play Console certificate fingerprint
+  - Upload from `app/release/app-release.aab`
 - [ ] Create GitHub release from tag with release notes
 
 ## Troubleshooting
 
 ### Common Issues
 1. **Build Failures**: Ensure `local.properties` contains required API keys
-2. **WorkManager Issues**: Check device battery optimization settings
-3. **Firebase Issues**: Verify `google-services.json` is present and valid
-4. **Compose Issues**: Clean and rebuild project, check Compose compiler version
+2. **Signing Key Mismatch**: If Google Play rejects your bundle with "signed with the wrong key" error, ensure you built locally with the correct keystore. Never upload AAB from GitHub Actions (see Issue #438)
+3. **WorkManager Issues**: Check device battery optimization settings
+4. **Firebase Issues**: Verify `google-services.json` is present and valid
+5. **Compose Issues**: Clean and rebuild project, check Compose compiler version
 
 ### Debugging Tools
 - Use `Timber.d()` for debug logging
diff --git a/.github/workflows/android-release.yml b/.github/workflows/android-release.yml
index 6f840b7..109b73e 100644
--- a/.github/workflows/android-release.yml
+++ b/.github/workflows/android-release.yml
@@ -4,11 +4,25 @@ name: Android Release Build
 # 1. Snapshot builds: Each time code changes on main branch
 # 2. Release builds: When a GitHub release is published (automatically attaches APK and AAB to release)
 # This allows developers and testers to easily download the latest release APK.
-# AAB (Android App Bundle) is provided for Google Play Store distribution.
+# AAB (Android App Bundle) is provided for GitHub release artifacts.
 #
-# See:
+# ⚠️ IMPORTANT: App Bundle Signing for Google Play Store
+# =====================================================
+# The AAB built in this workflow is signed with a CI keystore, NOT the keystore registered
+# in Google Play Console. DO NOT upload this AAB directly to Google Play Store.
+#
+# For Play Store releases, you MUST:
+# 1. Build locally: ./gradlew bundleRelease
+# 2. Verify local.properties has the correct keystore path and password
+# 3. Upload app/release/app-release.aab from your local machine to Google Play Console
+#
+# See Issue #438 for more details on signing key mismatches:
+# https://github.com/hossain-khan/android-remote-notify/issues/438
+#
+# References:
 # - https://github.com/hossain-khan/android-remote-notify/tree/main/keystore
-# - https://github.com/hossain-khan/android-remote-notify/blob/main/app/build.gradle.kts (signing configuration)
+# - https://github.com/hossain-khan/android-remote-notify/blob/main/app/build.gradle.kts (signing config)
+# - https://github.com/hossain-khan/android-remote-notify/.github/copilot-instructions.md (release process)
 
 on:
   push:
@@ -62,20 +76,48 @@ jobs:
         id: keystore
         run: |
           if [ -z "${{ secrets.KEYSTORE_BASE64 }}" ]; then
-            echo "⚠️ KEYSTORE_BASE64 secret is not set, using debug keystore for signing"
+            echo "⚠️ WARNING: KEYSTORE_BASE64 secret is not set"
+            echo "Using debug keystore for signing instead of release keystore"
+            echo "This build should NOT be uploaded to Google Play Store"
             echo "USE_RELEASE_KEYSTORE=false" >> $GITHUB_OUTPUT
           else
+            echo "📝 Attempting to decode release keystore from base64..."
             echo "${{ secrets.KEYSTORE_BASE64 }}" | base64 -d > keystore/remote-notify-release.keystore
             if [ ! -s keystore/remote-notify-release.keystore ]; then
-              echo "❌ Failed to decode keystore file"
+              echo "❌ ERROR: Failed to decode keystore file or keystore is empty"
               exit 1
             fi
-            echo "✅ Release keystore decoded successfully"
+            # Verify keystore file
+            KEYSTORE_SIZE=$(stat -f%z keystore/remote-notify-release.keystore 2>/dev/null || stat -c%s keystore/remote-notify-release.keystore 2>/dev/null)
+            echo "✅ Release keystore decoded successfully (size: $KEYSTORE_SIZE bytes)"
+            echo "⚠️ NOTE: AAB signed with CI keystore, not Google Play registr​ed keystore"
+            echo "For Play Store uploads, use locally-built AAB with correct keystore"
             echo "USE_RELEASE_KEYSTORE=true" >> $GITHUB_OUTPUT
           fi
 
       - name: Build Release APK and AAB
-        run: ./gradlew assembleRelease bundleRelease --parallel --daemon
+        run: |
+          echo "🏗️ Building Release APK and AAB..."
+          if [ "${{ steps.keystore.outputs.USE_RELEASE_KEYSTORE }}" = "true" ]; then
+            echo "📦 Signing with CI release keystore (NOT Google Play registered keystore)"
+          else
+            echo "📦 Signing with debug keystore (development only)"
+          fi
+          
+          ./gradlew assembleRelease bundleRelease --parallel --daemon
+          
+          if [ -f app/build/outputs/apk/release/app-release.apk ]; then
+            APK_SIZE=$(stat -f%z app/build/outputs/apk/release/app-release.apk 2>/dev/null || stat -c%s app/build/outputs/apk/release/app-release.apk 2>/dev/null)
+            echo "✅ APK built successfully (size: $APK_SIZE bytes)"
+          fi
+          
+          if [ -f app/build/outputs/bundle/release/app-release.aab ]; then
+            AAB_SIZE=$(stat -f%z app/build/outputs/bundle/release/app-release.aab 2>/dev/null || stat -c%s app/build/outputs/bundle/release/app-release.aab 2>/dev/null)
+            echo "✅ AAB built successfully (size: $AAB_SIZE bytes)"
+            echo "⚠️ REMINDER: This AAB is signed with CI keystore"
+            echo "⚠️ DO NOT upload this AAB to Google Play Store"
+            echo "✅ For Play Store, build locally: ./gradlew bundleRelease"
+          fi
         env:
           # Only set KEYSTORE_FILE when release keystore was decoded successfully
           # Otherwise, build.gradle.kts will fall back to debug keystore
@@ -113,6 +155,20 @@ jobs:
           path: artifact/remote-notify-v${{ steps.version.outputs.VERSION }}.aab
           retention-days: 30
 
+      # ⚠️ IMPORTANT: Signing & Google Play Store Upload
+      # ================================================
+      # The APK and AAB built here are for GitHub releases and testing ONLY.
+      # They are signed with the CI keystore, NOT the keystore registered in Google Play Console.
+      #
+      # FOR GOOGLE PLAY STORE RELEASES:
+      # 1. Do NOT use the AAB from this workflow
+      # 2. Build locally on your machine: ./gradlew bundleRelease
+      # 3. Verify local.properties has correct keystore path and password
+      # 4. Verify keystore SHA1 fingerprint matches Google Play Console
+      # 5. Upload app/release/app-release.aab to Google Play Console from your local machine
+      #
+      # See Issue #438 and copilot-instructions.md for detailed release process.
+
       # If this is running due to a GitHub release, attach the APK and AAB to the release
       - name: Attach APK and AAB to GitHub Release
         if: github.event_name == 'release'
@@ -182,3 +238,20 @@ jobs:
             cat upload_response_aab.json
             exit 1
           fi
+          
+          echo ""
+          echo "=================================="
+          echo "🔐 SIGNING NOTICE"
+          echo "=================================="
+          echo "✅ APK and AAB successfully built and attached to GitHub release"
+          echo "⚠️  These artifacts are signed with the CI keystore"
+          echo "⚠️  They are for testing and GitHub releases ONLY"
+          echo "❌ DO NOT upload to Google Play Store from this workflow"
+          echo ""
+          echo "📝 For Google Play Store releases:"
+          echo "   1. Build locally: ./gradlew bundleRelease"
+          echo "   2. Upload from local machine: app/release/app-release.aab"
+          echo ""
+          echo "📖 See .github/copilot-instructions.md for detailed release process"
+          echo "🔗 Issue #438: https://github.com/hossain-khan/android-remote-notify/issues/438"
+          echo "=================================="