diff --git a/src/java/com/android/internal/telephony/security/CellularNetworkSecuritySafetySource.java b/src/java/com/android/internal/telephony/security/CellularNetworkSecuritySafetySource.java
index 01c7c0d..605b197 100644
--- a/src/java/com/android/internal/telephony/security/CellularNetworkSecuritySafetySource.java
+++ b/src/java/com/android/internal/telephony/security/CellularNetworkSecuritySafetySource.java
@@ -25,6 +25,8 @@
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
+import android.content.res.Resources;
+import android.net.Uri;
 import android.safetycenter.SafetyCenterManager;
 import android.safetycenter.SafetyEvent;
 import android.safetycenter.SafetySourceData;
@@ -62,10 +64,6 @@
 
     private static final Intent CELLULAR_NETWORK_SECURITY_SETTINGS_INTENT =
             new Intent("android.settings.CELLULAR_NETWORK_SECURITY");
-    // TODO(b/321999913): direct to a help page URL e.g.
-    //                    new Intent(Intent.ACTION_VIEW, Uri.parse("https://..."));
-    private static final Intent LEARN_MORE_INTENT = new Intent();
-
     static final int NULL_CIPHER_STATE_ENCRYPTED = 0;
     static final int NULL_CIPHER_STATE_NOTIFY_ENCRYPTED = 1;
     static final int NULL_CIPHER_STATE_NOTIFY_NON_ENCRYPTED = 2;
@@ -223,7 +221,8 @@
                 builder = new SafetySourceIssue.Builder(
                         NULL_CIPHER_ISSUE_NON_ENCRYPTED_ID + "_" + subId,
                         context.getString(
-                            R.string.scNullCipherIssueNonEncryptedTitle, subInfo.getDisplayName()),
+                                R.string.scNullCipherIssueNonEncryptedTitle,
+                                subInfo.getDisplayName()),
                         context.getString(R.string.scNullCipherIssueNonEncryptedSummary),
                         SEVERITY_LEVEL_RECOMMENDATION,
                         NULL_CIPHER_ISSUE_NON_ENCRYPTED_ID);
@@ -232,7 +231,7 @@
                 builder = new SafetySourceIssue.Builder(
                         NULL_CIPHER_ISSUE_NON_ENCRYPTED_ID + "_" + subId,
                         context.getString(
-                            R.string.scNullCipherIssueEncryptedTitle, subInfo.getDisplayName()),
+                                R.string.scNullCipherIssueEncryptedTitle, subInfo.getDisplayName()),
                         context.getString(R.string.scNullCipherIssueEncryptedSummary),
                         SEVERITY_LEVEL_INFORMATION,
                         NULL_CIPHER_ISSUE_ENCRYPTED_ID);
@@ -240,26 +239,31 @@
             default:
                 throw new AssertionError();
         }
-
-        return Optional.of(
-                builder
-                    .setNotificationBehavior(SafetySourceIssue.NOTIFICATION_BEHAVIOR_IMMEDIATELY)
-                    .setIssueCategory(SafetySourceIssue.ISSUE_CATEGORY_DEVICE)
-                    .addAction(
+        builder
+                .setNotificationBehavior(
+                        SafetySourceIssue.NOTIFICATION_BEHAVIOR_IMMEDIATELY)
+                .setIssueCategory(SafetySourceIssue.ISSUE_CATEGORY_DEVICE)
+                .addAction(
                         new SafetySourceIssue.Action.Builder(
                                 NULL_CIPHER_ACTION_SETTINGS_ID,
                                 context.getString(R.string.scNullCipherIssueActionSettings),
                                 mSafetyCenterManagerWrapper.getActivityPendingIntent(
                                         context, CELLULAR_NETWORK_SECURITY_SETTINGS_INTENT))
-                            .build())
-                    .addAction(
-                        new SafetySourceIssue.Action.Builder(
-                                NULL_CIPHER_ACTION_LEARN_MORE_ID,
-                                context.getString(R.string.scNullCipherIssueActionLearnMore),
-                                mSafetyCenterManagerWrapper.getActivityPendingIntent(
-                                        context, LEARN_MORE_INTENT))
-                            .build())
-                    .build());
+                                .build());
+
+        Intent learnMoreIntent = getLearnMoreIntent(context);
+        if (learnMoreIntent != null) {
+            builder.addAction(
+                    new SafetySourceIssue.Action.Builder(
+                            NULL_CIPHER_ACTION_LEARN_MORE_ID,
+                            context.getString(
+                                    R.string.scNullCipherIssueActionLearnMore),
+                            mSafetyCenterManagerWrapper.getActivityPendingIntent(
+                                    context, learnMoreIntent))
+                            .build());
+        }
+
+        return Optional.of(builder.build());
     }
 
     /** Builds the identity disclosure issue if it's enabled and there are disclosures to report. */
@@ -271,7 +275,8 @@
 
         SubscriptionInfoInternal subInfo =
                 mSubscriptionManagerService.getSubscriptionInfoInternal(subId);
-        return Optional.of(
+
+        SafetySourceIssue.Builder builder =
                 new SafetySourceIssue.Builder(
                         IDENTIFIER_DISCLOSURE_ISSUE_ID + "_" + subId,
                         context.getString(R.string.scIdentifierDisclosureIssueTitle),
@@ -283,23 +288,51 @@
                                 subInfo.getDisplayName()),
                         SEVERITY_LEVEL_RECOMMENDATION,
                         IDENTIFIER_DISCLOSURE_ISSUE_ID)
-                    .setNotificationBehavior(SafetySourceIssue.NOTIFICATION_BEHAVIOR_IMMEDIATELY)
-                    .setIssueCategory(SafetySourceIssue.ISSUE_CATEGORY_DEVICE)
-                    .addAction(
-                        new SafetySourceIssue.Action.Builder(
-                                NULL_CIPHER_ACTION_SETTINGS_ID,
-                                context.getString(R.string.scNullCipherIssueActionSettings),
-                                mSafetyCenterManagerWrapper.getActivityPendingIntent(
-                                        context, CELLULAR_NETWORK_SECURITY_SETTINGS_INTENT))
-                            .build())
-                    .addAction(
-                        new SafetySourceIssue.Action.Builder(
-                                NULL_CIPHER_ACTION_LEARN_MORE_ID,
-                                context.getString(R.string.scNullCipherIssueActionLearnMore),
-                                mSafetyCenterManagerWrapper.getActivityPendingIntent(
-                                        context, LEARN_MORE_INTENT))
-                            .build())
-                .build());
+                        .setNotificationBehavior(
+                                SafetySourceIssue.NOTIFICATION_BEHAVIOR_IMMEDIATELY)
+                        .setIssueCategory(SafetySourceIssue.ISSUE_CATEGORY_DEVICE)
+                        .addAction(
+                                new SafetySourceIssue.Action.Builder(
+                                        NULL_CIPHER_ACTION_SETTINGS_ID,
+                                        context.getString(
+                                                R.string.scNullCipherIssueActionSettings),
+                                        mSafetyCenterManagerWrapper.getActivityPendingIntent(
+                                                context,
+                                                CELLULAR_NETWORK_SECURITY_SETTINGS_INTENT))
+                                        .build());
+
+        Intent learnMoreIntent = getLearnMoreIntent(context);
+        if (learnMoreIntent != null) {
+            builder.addAction(
+                    new SafetySourceIssue.Action.Builder(
+                            NULL_CIPHER_ACTION_LEARN_MORE_ID,
+                            context.getString(R.string.scNullCipherIssueActionLearnMore),
+                            mSafetyCenterManagerWrapper.getActivityPendingIntent(
+                                    context, learnMoreIntent)).build()
+            );
+        }
+
+        return Optional.of(builder.build());
+    }
+
+    /**
+     * Return Intent for learn more action, or null if resource associated with the Intent
+     * uri is
+     * missing or empty.
+     */
+    private Intent getLearnMoreIntent(Context context) {
+        String learnMoreUri;
+        try {
+            learnMoreUri = context.getString(R.string.scCellularNetworkSecurityLearnMore);
+        } catch (Resources.NotFoundException e) {
+            return null;
+        }
+
+        if (learnMoreUri.isEmpty()) {
+            return null;
+        }
+
+        return new Intent(Intent.ACTION_VIEW, Uri.parse(learnMoreUri));
     }
 
     /** A wrapper around {@link SafetyCenterManager} that can be instrumented in tests. */
@@ -344,7 +377,7 @@
         private IdentifierDisclosure(int count, Instant start, Instant end) {
             mDisclosureCount = count;
             mWindowStart = start;
-            mWindowEnd  = end;
+            mWindowEnd = end;
         }
 
         private int getDisclosureCount() {
diff --git a/tests/telephonytests/src/com/android/internal/telephony/security/CellularNetworkSecuritySafetySourceTest.java b/tests/telephonytests/src/com/android/internal/telephony/security/CellularNetworkSecuritySafetySourceTest.java
index d8554a7..77759a0 100644
--- a/tests/telephonytests/src/com/android/internal/telephony/security/CellularNetworkSecuritySafetySourceTest.java
+++ b/tests/telephonytests/src/com/android/internal/telephony/security/CellularNetworkSecuritySafetySourceTest.java
@@ -36,6 +36,7 @@
 import android.content.Context;
 import android.content.Intent;
 import android.safetycenter.SafetySourceData;
+import android.safetycenter.SafetySourceIssue;
 import android.util.Singleton;
 
 import com.android.internal.R;
@@ -50,6 +51,7 @@
 import org.mockito.ArgumentCaptor;
 
 import java.time.Instant;
+import java.util.List;
 
 public final class CellularNetworkSecuritySafetySourceTest extends TelephonyTest {
 
@@ -76,6 +78,8 @@
 
         mContextFixture.putResource(R.string.scCellularNetworkSecurityTitle, "fake");
         mContextFixture.putResource(R.string.scCellularNetworkSecuritySummary, "fake");
+        mContextFixture.putResource(R.string.scCellularNetworkSecurityLearnMore,
+                "https://support.google.com/android?p=cellular_security");
         mContextFixture.putResource(R.string.scNullCipherIssueNonEncryptedTitle, "fake %1$s");
         mContextFixture.putResource(R.string.scNullCipherIssueNonEncryptedSummary, "fake");
         mContextFixture.putResource(R.string.scNullCipherIssueEncryptedTitle, "fake %1$s");
@@ -265,4 +269,24 @@
         assertThat(data.getAllValues().get(3).getStatus()).isNotNull();
         assertThat(data.getAllValues().get(3).getIssues()).hasSize(2);
     }
+
+    @Test
+    public void learnMoreLinkEmpty_learnMoreIsHidden() {
+        mContextFixture.putResource(R.string.scCellularNetworkSecurityLearnMore, "");
+
+        ArgumentCaptor<SafetySourceData> data = ArgumentCaptor.forClass(SafetySourceData.class);
+
+        mSafetySource.setNullCipherIssueEnabled(mContext, true);
+        mSafetySource.setNullCipherState(mContext, 0, NULL_CIPHER_STATE_NOTIFY_NON_ENCRYPTED);
+        mSafetySource.setIdentifierDisclosureIssueEnabled(mContext, true);
+        mSafetySource.setIdentifierDisclosure(mContext, 0, 12, Instant.now(), Instant.now());
+
+        verify(mSafetyCenterManagerWrapper, times(4)).setSafetySourceData(data.capture());
+        List<SafetySourceIssue.Action> actions = data.getAllValues().get(
+                3).getIssues().getFirst().getActions();
+
+        // we only see the action that takes you to the settings page
+        assertThat(actions).hasSize(1);
+        assertThat(actions.getFirst().getId()).isEqualTo("cellular_security_settings");
+    }
 }
\ No newline at end of file