diff --git a/src/com/android/server/telecom/PhoneAccountRegistrar.java b/src/com/android/server/telecom/PhoneAccountRegistrar.java
index b5b22ef..2669a1d 100644
--- a/src/com/android/server/telecom/PhoneAccountRegistrar.java
+++ b/src/com/android/server/telecom/PhoneAccountRegistrar.java
@@ -29,6 +29,7 @@
 import android.graphics.BitmapFactory;
 import android.graphics.drawable.Icon;
 import android.net.Uri;
+import android.os.Binder;
 import android.os.Bundle;
 import android.os.AsyncTask;
 import android.os.PersistableBundle;
@@ -132,9 +133,14 @@
     }
 
     public static final String FILE_NAME = "phone-account-registrar-state.xml";
+    public static final String ICON_ERROR_MSG =
+            "Icon cannot be written to memory. Try compressing or downsizing";
     @VisibleForTesting
     public static final int EXPECTED_STATE_VERSION = 9;
     public static final int MAX_PHONE_ACCOUNT_REGISTRATIONS = 10;
+    public static final int MAX_PHONE_ACCOUNT_EXTRAS_KEY_PAIR_LIMIT = 100;
+    public static final int MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT = 256;
+    public static final int MAX_SCHEMES_PER_ACCOUNT = 10;
 
     /** Keep in sync with the same in SipSettings.java */
     private static final String SIP_SHARED_PREFERENCES = "SIP_PREFERENCES";
@@ -751,6 +757,15 @@
         return getPhoneAccountHandles(0, null, packageName, false, userHandle);
     }
 
+
+    /**
+     * includes disabled, includes crossUserAccess
+     */
+    public List<PhoneAccountHandle> getAllPhoneAccountHandlesForPackage(UserHandle userHandle,
+            String packageName) {
+        return getPhoneAccountHandles(0, null, packageName, true /* includeDisabled */, userHandle);
+    }
+
     /**
      * Determines if a {@link PhoneAccountHandle} is for a self-managed {@link ConnectionService}.
      * @param handle The handle.
@@ -770,8 +785,11 @@
      * Performs checks before calling addOrReplacePhoneAccount(PhoneAccount)
      *
      * @param account The {@code PhoneAccount} to add or replace.
-     * @throws SecurityException if package does not have BIND_TELECOM_CONNECTION_SERVICE permission
+     * @throws SecurityException        if package does not have BIND_TELECOM_CONNECTION_SERVICE
+     *                                  permission
      * @throws IllegalArgumentException if MAX_PHONE_ACCOUNT_REGISTRATIONS are reached
+     * @throws IllegalArgumentException if MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT is reached
+     * @throws IllegalArgumentException if writing the Icon to memory will cause an Exception
      */
     public void registerPhoneAccount(PhoneAccount account) {
         // Enforce the requirement that a connection service for a phone account has the correct
@@ -783,21 +801,155 @@
             throw new SecurityException("PhoneAccount connection service requires "
                     + "BIND_TELECOM_CONNECTION_SERVICE permission.");
         }
-        //Enforce an upper bound on the number of PhoneAccount's a package can register.
-        // Most apps should only require 1-2.
-        if (getPhoneAccountsForPackage(
-                account.getAccountHandle().getComponentName().getPackageName(),
-                account.getAccountHandle().getUserHandle()).size()
+        enforceCharacterLimit(account);
+        enforceIconSizeLimit(account);
+        enforceMaxPhoneAccountLimit(account);
+        addOrReplacePhoneAccount(account);
+    }
+
+    /**
+     * Enforce an upper bound on the number of PhoneAccount's a package can register.
+     * Most apps should only require 1-2.  * Include disabled accounts.
+     *
+     * @param account to enforce check on
+     * @throws IllegalArgumentException if MAX_PHONE_ACCOUNT_REGISTRATIONS are reached
+     */
+    private void enforceMaxPhoneAccountLimit(@NonNull PhoneAccount account) {
+        final PhoneAccountHandle accountHandle = account.getAccountHandle();
+        final UserHandle user = accountHandle.getUserHandle();
+        final ComponentName componentName = accountHandle.getComponentName();
+
+        if (getPhoneAccountHandles(0, null, componentName.getPackageName(),
+                true /* includeDisabled */, user).size()
                 >= MAX_PHONE_ACCOUNT_REGISTRATIONS) {
-            Log.w(this, "Phone account %s reached max registration limit for package",
-                    account.getAccountHandle());
+            EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                    "enforceMaxPhoneAccountLimit");
             throw new IllegalArgumentException(
                     "Error, cannot register phone account " + account.getAccountHandle()
                             + " because the limit, " + MAX_PHONE_ACCOUNT_REGISTRATIONS
                             + ", has been reached");
         }
+    }
+    /**
+     * determine if there will be an issue writing the icon to memory
+     *
+     * @param account to enforce check on
+     * @throws IllegalArgumentException if writing the Icon to memory will cause an Exception
+     */
+    @VisibleForTesting
+    public void enforceIconSizeLimit(PhoneAccount account) {
+        if (account.getIcon() == null) {
+            return;
+        }
+        String text = "";
+        // convert the icon into a Base64 String
+        try {
+            text = XmlSerialization.writeIconToBase64String(account.getIcon());
+        } catch (IOException e) {
+            EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                    "enforceIconSizeLimit");
+            throw new IllegalArgumentException(ICON_ERROR_MSG);
+        }
+    }
 
-        addOrReplacePhoneAccount(account);
+    /**
+     * All {@link PhoneAccount} and{@link PhoneAccountHandle} String and Char-Sequence fields
+     * should be restricted to character limit of MAX_PHONE_ACCOUNT_CHAR_LIMIT to prevent exceptions
+     * when writing large character streams to XML-Serializer.
+     *
+     * @param account to enforce character limit checks on
+     * @throws IllegalArgumentException if MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT reached
+     */
+    public void enforceCharacterLimit(PhoneAccount account) {
+        if (account == null) {
+            return;
+        }
+        PhoneAccountHandle handle = account.getAccountHandle();
+
+        String[] fields =
+                {"Package Name", "Class Name", "PhoneAccountHandle Id", "Label", "ShortDescription",
+                        "GroupId", "Address", "SubscriptionAddress"};
+        CharSequence[] args = {handle.getComponentName().getPackageName(),
+                handle.getComponentName().getClassName(), handle.getId(), account.getLabel(),
+                account.getShortDescription(), account.getGroupId(),
+                (account.getAddress() != null ? account.getAddress().toString() : ""),
+                (account.getSubscriptionAddress() != null ?
+                        account.getSubscriptionAddress().toString() : "")};
+
+        for (int i = 0; i < fields.length; i++) {
+            if (args[i] != null && args[i].length() > MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT) {
+                EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                        "enforceCharacterLimit");
+                throw new IllegalArgumentException("The PhoneAccount or PhoneAccountHandle"
+                        + fields[i] + " field has an invalid character count. PhoneAccount and "
+                        + "PhoneAccountHandle String and Char-Sequence fields are limited to "
+                        + MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT + " characters.");
+            }
+        }
+
+        // Enforce limits on the URI Schemes provided
+        enforceLimitsOnSchemes(account);
+
+        // Enforce limit on the PhoneAccount#mExtras
+        Bundle extras = account.getExtras();
+        if (extras != null) {
+            if (extras.keySet().size() > MAX_PHONE_ACCOUNT_EXTRAS_KEY_PAIR_LIMIT) {
+                EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                        "enforceCharacterLimit");
+                throw new IllegalArgumentException("The PhoneAccount#mExtras is limited to " +
+                        MAX_PHONE_ACCOUNT_EXTRAS_KEY_PAIR_LIMIT + " (key,value) pairs.");
+            }
+
+            for (String key : extras.keySet()) {
+                Object value = extras.get(key);
+
+                if ((key != null && key.length() > MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT) ||
+                        (value instanceof String &&
+                                ((String) value).length() > MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT)) {
+                    EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                            "enforceCharacterLimit");
+                    throw new IllegalArgumentException("The PhoneAccount#mExtras contains a String"
+                            + " key or value that has an invalid character count. PhoneAccount and "
+                            + "PhoneAccountHandle String and Char-Sequence fields are limited to "
+                            + MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT + " characters.");
+                }
+            }
+        }
+    }
+
+    /**
+     * Enforce a character limit on all PA and PAH string or char-sequence fields.
+     *
+     * @param account to enforce check on
+     * @throws IllegalArgumentException if MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT reached
+     */
+    @VisibleForTesting
+    public void enforceLimitsOnSchemes(@NonNull PhoneAccount account) {
+        List<String> schemes = account.getSupportedUriSchemes();
+
+        if (schemes == null) {
+            return;
+        }
+
+        if (schemes.size() > MAX_SCHEMES_PER_ACCOUNT) {
+            EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                    "enforceLimitsOnSchemes");
+            throw new IllegalArgumentException(
+                    "Error, cannot register phone account " + account.getAccountHandle()
+                            + " because the URI scheme limit of "
+                            + MAX_SCHEMES_PER_ACCOUNT + " has been reached");
+        }
+
+        for (String scheme : schemes) {
+            if (scheme.length() > MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT) {
+                EventLog.writeEvent(0x534e4554, "259064622", Binder.getCallingUid(),
+                        "enforceLimitsOnSchemes");
+                throw new IllegalArgumentException(
+                        "Error, cannot register phone account " + account.getAccountHandle()
+                                + " because the max scheme limit of "
+                                + MAX_PHONE_ACCOUNT_FIELD_CHAR_LIMIT + " has been reached");
+            }
+        }
     }
 
     /**
@@ -1521,17 +1673,20 @@
         protected void writeIconIfNonNull(String tagName, Icon value, XmlSerializer serializer)
                 throws IOException {
             if (value != null) {
-                ByteArrayOutputStream stream = new ByteArrayOutputStream();
-                value.writeToStream(stream);
-                byte[] iconByteArray = stream.toByteArray();
-                String text = Base64.encodeToString(iconByteArray, 0, iconByteArray.length, 0);
-
+                String text = writeIconToBase64String(value);
                 serializer.startTag(null, tagName);
                 serializer.text(text);
                 serializer.endTag(null, tagName);
             }
         }
 
+        public static String writeIconToBase64String(Icon icon) throws IOException {
+            ByteArrayOutputStream stream = new ByteArrayOutputStream();
+            icon.writeToStream(stream);
+            byte[] iconByteArray = stream.toByteArray();
+            return Base64.encodeToString(iconByteArray, 0, iconByteArray.length, 0);
+        }
+
         protected void writeLong(String tagName, long value, XmlSerializer serializer)
                 throws IOException {
             serializer.startTag(null, tagName);
diff --git a/src/com/android/server/telecom/TelecomServiceImpl.java b/src/com/android/server/telecom/TelecomServiceImpl.java
index f286f2f..6d8a2f3 100644
--- a/src/com/android/server/telecom/TelecomServiceImpl.java
+++ b/src/com/android/server/telecom/TelecomServiceImpl.java
@@ -66,7 +66,9 @@
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 // TODO: Needed for move to system service: import com.android.internal.R;
 
@@ -306,7 +308,7 @@
                 try {
                     Log.startSession("TSI.gPAFP");
                     return new ParceledListSlice<>(mPhoneAccountRegistrar
-                            .getPhoneAccountsForPackage(packageName, callingUserHandle));
+                            .getAllPhoneAccountHandlesForPackage(callingUserHandle, packageName));
                 } catch (Exception e) {
                     Log.e(this, e, "getPhoneAccountsForPackage %s", packageName);
                     throw e;
diff --git a/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java b/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
index 00ef87c..7673e82 100644
--- a/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
+++ b/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
@@ -22,8 +22,18 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyObject;
+import static org.mockito.ArgumentMatchers.isA;
 import static org.mockito.Matchers.anyInt;
 import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.clearInvocations;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.content.ComponentName;
@@ -70,6 +80,8 @@
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -82,6 +94,9 @@
     private static final int MAX_VERSION = Integer.MAX_VALUE;
     private static final String FILE_NAME = "phone-account-registrar-test-1223.xml";
     private static final String TEST_LABEL = "right";
+    private static final String TEST_ID = "123";
+    private final String PACKAGE_1 = "PACKAGE_1";
+    private final String PACKAGE_2 = "PACKAGE_2";
     private PhoneAccountRegistrar mRegistrar;
     @Mock private TelecomManager mTelecomManager;
     @Mock private DefaultDialerCache mDefaultDialerCache;
@@ -1006,6 +1021,92 @@
         assertFalse(PhoneAccountHandle.areFromSamePackage(null, d));
     }
 
+    /**
+     * Ensure an IllegalArgumentException is thrown when adding more than 10 schemes for a single
+     * account
+     */
+    @Test
+    public void testLimitOnSchemeCount() {
+        PhoneAccountHandle handle = makeQuickAccountHandle(TEST_ID);
+        PhoneAccount.Builder builder = new PhoneAccount.Builder(handle, TEST_LABEL);
+        for (int i = 0; i < PhoneAccountRegistrar.MAX_PHONE_ACCOUNT_REGISTRATIONS + 1; i++) {
+            builder.addSupportedUriScheme(Integer.toString(i));
+        }
+        try {
+            mRegistrar.enforceLimitsOnSchemes(builder.build());
+            fail("should have hit exception in enforceLimitOnSchemes");
+        } catch (IllegalArgumentException e) {
+            // pass test
+        }
+    }
+
+    /**
+     * Ensure an IllegalArgumentException is thrown when adding more 256 chars for a single
+     * account
+     */
+    @Test
+    public void testLimitOnSchemeLength() {
+        PhoneAccountHandle handle = makeQuickAccountHandle(TEST_ID);
+        PhoneAccount.Builder builder = new PhoneAccount.Builder(handle, TEST_LABEL);
+        builder.addSupportedUriScheme(generateStringOfLen(257));
+        try {
+            mRegistrar.enforceLimitsOnSchemes(builder.build());
+            fail("should have hit exception in enforceLimitOnSchemes");
+        } catch (IllegalArgumentException e) {
+            // pass test
+        }
+    }
+
+    /**
+     * Ensure an IllegalArgumentException is thrown when adding an address over the limit
+     */
+    @Test
+    public void testLimitOnAddress() {
+        String text = generateStringOfLen(100);
+        PhoneAccountHandle handle = makeQuickAccountHandle(TEST_ID);
+        PhoneAccount.Builder builder = new PhoneAccount.Builder(handle,TEST_LABEL)
+                .setAddress(Uri.fromParts(text, text, text));
+        try {
+            mRegistrar.enforceCharacterLimit(builder.build());
+            fail("failed to throw IllegalArgumentException");
+        } catch (IllegalArgumentException e) {
+            // pass test
+        }
+        finally {
+            mRegistrar.unregisterPhoneAccount(handle);
+        }
+    }
+
+    /**
+     * Ensure an IllegalArgumentException is thrown when an Icon that throws an IOException is given
+     */
+    @Test
+    public void testLimitOnIcon() throws Exception {
+        Icon mockIcon = mock(Icon.class);
+        // GIVEN
+        PhoneAccount.Builder builder = new PhoneAccount.Builder(
+                makeQuickAccountHandle(TEST_ID), TEST_LABEL).setIcon(mockIcon);
+        try {
+            // WHEN
+            Mockito.doThrow(new IOException())
+                    .when(mockIcon).writeToStream(any(OutputStream.class));
+            //THEN
+            mRegistrar.enforceIconSizeLimit(builder.build());
+            fail("failed to throw IllegalArgumentException");
+        } catch (IllegalArgumentException e) {
+            // pass test
+            assertTrue(e.getMessage().contains(PhoneAccountRegistrar.ICON_ERROR_MSG));
+        }
+    }
+
+   private String generateStringOfLen(int len){
+       StringBuilder sb = new StringBuilder();
+       for(int i=0; i < len; i++){
+           sb.append("a");
+       }
+       return sb.toString();
+   }
+
     private static ComponentName makeQuickConnectionServiceComponentName() {
         return new ComponentName(
                 "com.android.server.telecom.tests",
diff --git a/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java b/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
index 126c0c0..c2d97e6 100644
--- a/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
+++ b/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
@@ -452,7 +452,7 @@
             add(SIP_PA_HANDLE_17);
         }};
         when(mFakePhoneAccountRegistrar
-                .getPhoneAccountsForPackage(anyString(), any(UserHandle.class)))
+                .getAllPhoneAccountHandlesForPackage(any(UserHandle.class), anyString()))
                 .thenReturn(phoneAccountHandleList);
         makeAccountsVisibleToAllUsers(TEL_PA_HANDLE_16, SIP_PA_HANDLE_17);
         assertEquals(phoneAccountHandleList,