diff --git a/android/OldPhoneNumberUtils.cpp b/android/OldPhoneNumberUtils.cpp
index 9c2f20e..9846a1c 100644
--- a/android/OldPhoneNumberUtils.cpp
+++ b/android/OldPhoneNumberUtils.cpp
@@ -154,33 +154,6 @@
     return state == 6 || state == 7 || state == 8;
 }
 
-/** or -1 if both are negative */
-static int minPositive(int a, int b)
-{
-    if (a >= 0 && b >= 0) {
-        return (a < b) ? a : b;
-    } else if (a >= 0) { /* && b < 0 */
-        return a;
-    } else if (b >= 0) { /* && a < 0 */
-        return b;
-    } else { /* a < 0 && b < 0 */
-        return -1;
-    }
-}
-
-/**
- * Return the offset into a of the first appearance of b, or -1 if there
- * is no such character in a.
- */
-static int indexOf(const char *a, char b) {
-    const char *ix = strchr(a, b);
-
-    if (ix == NULL)
-        return -1;
-    else
-        return ix - a;
-}
-
 /**
  * Compare phone numbers a and b, return true if they're identical
  * enough for caller ID purposes.
@@ -270,15 +243,15 @@
      *     (for this, a '0' and a '00' prefix would have succeeded above)
      */
 
-    if (matchIntlPrefix(a, ia + 1) && matchIntlPrefix(b, ib +1)) {
+    if (matchIntlPrefix(a, ia + 1) && matchIntlPrefix(b, ib + 1)) {
         return true;
     }
 
-    if (matchTrunkPrefix(a, ia + 1) && matchIntlPrefixAndCC(b, ib +1)) {
+    if (matchTrunkPrefix(a, ia + 1) && matchIntlPrefixAndCC(b, ib + 1)) {
         return true;
     }
 
-    if (matchTrunkPrefix(b, ib + 1) && matchIntlPrefixAndCC(a, ia +1)) {
+    if (matchTrunkPrefix(b, ib + 1) && matchIntlPrefixAndCC(a, ia + 1)) {
         return true;
     }
 
@@ -292,7 +265,9 @@
      */
     bool aPlusFirst = (*a == '+');
     bool bPlusFirst = (*b == '+');
-    if (ia < 4 && ib < 4 && (aPlusFirst || bPlusFirst) && !(aPlusFirst && bPlusFirst)) {
+    bool aIgnoreUnmatched = aPlusFirst && (ia - ib) >= 0 && (ia - ib) <= 1;
+    bool bIgnoreUnmatched = bPlusFirst && (ib - ia) >= 0 && (ib - ia) <= 1;
+    if (ia < 4 && ib < 4 && (aIgnoreUnmatched || bIgnoreUnmatched) && !(aPlusFirst && bPlusFirst)) {
         return true;
     }
 
diff --git a/android/OldPhoneNumberUtilsTest.cpp b/android/OldPhoneNumberUtilsTest.cpp
new file mode 100644
index 0000000..777ae71
--- /dev/null
+++ b/android/OldPhoneNumberUtilsTest.cpp
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//
+// Note that similar (or almost same) tests exist in Java side (See
+// DatabaseGeneralTest.java in AndroidTests). The differences are:
+// - this test is quite easy to do (You can do it in your Unix PC)
+// - this test is not automatically executed by build servers
+//
+// You should also execute the test before submitting this.
+//
+
+#include "PhoneNumberUtils.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include <gtest/gtest.h>
+
+using namespace android;
+
+
+TEST(PhoneNumberUtils, compareLooseNullOrEmpty) {
+    EXPECT_FALSE(phone_number_compare_loose(NULL, NULL));
+    EXPECT_FALSE(phone_number_compare_loose("", NULL));
+    EXPECT_FALSE(phone_number_compare_loose(NULL, ""));
+    EXPECT_FALSE(phone_number_compare_loose("", ""));
+}
+
+TEST(PhoneNumberUtils, compareLooseDigitsSame) {
+    EXPECT_TRUE(phone_number_compare_loose("999", "999"));
+    EXPECT_TRUE(phone_number_compare_loose("119", "119"));
+}
+
+TEST(PhoneNumberUtils, compareLooseDigitsDifferent) {
+    EXPECT_FALSE(phone_number_compare_loose("123456789", "923456789"));
+    EXPECT_FALSE(phone_number_compare_loose("123456789", "123456781"));
+    EXPECT_FALSE(phone_number_compare_loose("123456789", "1234567890"));
+    EXPECT_TRUE(phone_number_compare_loose("123456789", "0123456789"));
+}
+
+TEST(PhoneNumberUtils, compareLooseGoogle) {
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "6502530000"));
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "650 253 0000"));
+    EXPECT_TRUE(phone_number_compare_loose("650 253 0000", "6502530000"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkPrefixUs) {
+    // trunk (NDD) prefix must be properly handled in US
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "1-650-253-0000"));
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "   1-650-253-0000"));
+
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "11-650-253-0000"));
+    EXPECT_TRUE(phone_number_compare_loose("650-253-0000", "0-650-253-0000"));
+    EXPECT_TRUE(phone_number_compare_loose("555-4141", "+1-700-555-4141"));
+
+    EXPECT_TRUE(phone_number_compare_loose("+1 650-253-0000", "6502530000"));
+    EXPECT_TRUE(phone_number_compare_loose("001 650-253-0000", "6502530000"));
+    EXPECT_TRUE(phone_number_compare_loose("0111 650-253-0000", "6502530000"));
+}
+
+TEST(PhoneNumberUtils, compareLooseDifferentCountryCode) {
+    EXPECT_FALSE(phone_number_compare_loose("+19012345678", "+819012345678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkJapan) {
+    EXPECT_TRUE(phone_number_compare_loose("+31771234567", "0771234567"));
+    EXPECT_TRUE(phone_number_compare_loose("090-1234-5678", "+819012345678"));
+    EXPECT_TRUE(phone_number_compare_loose("090(1234)5678", "+819012345678"));
+    EXPECT_TRUE(phone_number_compare_loose("090-1234-5678", "+81-90-1234-5678"));
+
+    EXPECT_TRUE(phone_number_compare_loose("+819012345678", "090-1234-5678"));
+    EXPECT_TRUE(phone_number_compare_loose("+819012345678", "090(1234)5678"));
+    EXPECT_TRUE(phone_number_compare_loose("+81-90-1234-5678", "090-1234-5678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkRussia) {
+    EXPECT_TRUE(phone_number_compare_loose("+79161234567", "89161234567"));
+
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkFrance) {
+    EXPECT_TRUE(phone_number_compare_loose("+33123456789", "0123456789"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkHungary) {
+    EXPECT_TRUE(phone_number_compare_loose("+36 1 234 5678", "06 1234-5678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkMexico) {
+    EXPECT_TRUE(phone_number_compare_loose("+52 55 1234 5678", "01 55 1234 5678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkMongolia) {
+    EXPECT_TRUE(phone_number_compare_loose("+976 1 123 4567", "01 1 23 4567"));
+    EXPECT_TRUE(phone_number_compare_loose("+976 2 234 5678", "02 2 34 5678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkNetherlandsCities) {
+    EXPECT_TRUE(phone_number_compare_loose("+31771234567", "0771234567"));
+}
+
+TEST(PhoneNumberUtils, compareLooseInternationalJapan) {
+    EXPECT_FALSE(phone_number_compare_loose("+818012345678", "+819012345678"));
+    EXPECT_TRUE(phone_number_compare_loose("+819012345678", "+819012345678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTrunkIgnoreJapan) {
+    // Trunk prefix must not be ignored in Japan
+    EXPECT_TRUE(phone_number_compare_loose("090-1234-5678", "90-1234-5678"));
+    EXPECT_FALSE(phone_number_compare_loose("090-1234-5678", "080-1234-5678"));
+    EXPECT_FALSE(phone_number_compare_loose("090-1234-5678", "190-1234-5678"));
+    EXPECT_FALSE(phone_number_compare_loose("090-1234-5678", "890-1234-5678"));
+    EXPECT_FALSE(phone_number_compare_loose("080-1234-5678", "+819012345678"));
+    EXPECT_FALSE(phone_number_compare_loose("+81-90-1234-5678", "+81-090-1234-5678"));
+}
+
+TEST(PhoneNumberUtils, compareLooseInternationalNational) {
+    EXPECT_TRUE(phone_number_compare_loose("+593(800)123-1234", "8001231234"));
+}
+
+TEST(PhoneNumberUtils, compareLooseTwoContinuousZeros) {
+    // Two continuous 0 at the begining of the phone string should be
+    // treated as trunk prefix for caller id purposes.
+    EXPECT_TRUE(phone_number_compare_loose("008001231234", "8001231234"));
+}
+
+TEST(PhoneNumberUtils, compareLooseCallerIdThailandUs) {
+    // Test broken caller ID seen on call from Thailand to the US
+    EXPECT_TRUE(phone_number_compare_loose("+66811234567", "166811234567"));
+    // Confirm that the bug found before does not re-appear.
+    EXPECT_TRUE(phone_number_compare_loose("650-000-3456", "16500003456"));
+    EXPECT_TRUE(phone_number_compare_loose("011 1 7005554141", "+17005554141"));
+    EXPECT_FALSE(phone_number_compare_loose("011 11 7005554141", "+17005554141"));
+    EXPECT_TRUE(phone_number_compare_loose("+44 207 792 3490", "00 207 792 3490"));
+}
+
+TEST(PhoneNumberUtils, compareLooseNamp1661) {
+    // This is not related to Thailand case. NAMP "1" + region code "661".
+    EXPECT_TRUE(phone_number_compare_loose("16610001234", "6610001234"));
+}
+
+TEST(PhoneNumberUtils, compareLooseAlphaDifferent) {
+    // We also need to compare two alpha addresses to make sure two different strings
+    // aren't treated as the same addresses. This is relevant to SMS as SMS sender may
+    // contain all alpha chars.
+    EXPECT_TRUE(phone_number_compare_loose("abcd", "bcde"));
+}
+
+TEST(PhoneNumberUtils, compareLooseAlphaNumericDifferent) {
+    EXPECT_FALSE(phone_number_compare_loose("1-800-flowers", "800-flowers"));
+    // TODO: "flowers" and "adcdefg" should not match
+    //EXPECT_FALSE(phone_number_compare_loose("1-800-flowers", "1-800-abcdefg"));
+}
+
+// TODO: we currently do not support this comparison. It maybe nice to support this
+// TODO: in the future.
+//TEST(PhoneNumberUtils, compareLooseLettersToDigits) {
+//  EXPECT_TRUE(phone_number_compare_loose("1-800-flowers", "1-800-356-9377"));
+//}
+
+TEST(PhoneNumberUtils, compareLooseWrongPrefix) {
+    // Japan
+    EXPECT_FALSE(phone_number_compare_loose("290-1234-5678", "+819012345678"));
+    EXPECT_FALSE(phone_number_compare_loose("+819012345678", "290-1234-5678"));
+    // USA
+    EXPECT_TRUE(phone_number_compare_loose("0550-450-3605", "+15504503605"));
+    EXPECT_FALSE(phone_number_compare_loose("550-450-3605", "+14504503605"));
+    EXPECT_FALSE(phone_number_compare_loose("550-450-3605", "+15404503605"));
+    EXPECT_FALSE(phone_number_compare_loose("550-450-3605", "+15514503605"));
+    EXPECT_FALSE(phone_number_compare_loose("5504503605", "+14504503605"));
+
+    EXPECT_FALSE(phone_number_compare_loose("+14504503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_loose("+15404503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_loose("+15514503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_loose("+14504503605", "5504503605"));
+}
+
+
diff --git a/android/PhoneNumberUtils.cpp b/android/PhoneNumberUtils.cpp
index a753f42..f986709 100644
--- a/android/PhoneNumberUtils.cpp
+++ b/android/PhoneNumberUtils.cpp
@@ -231,8 +231,8 @@
 
 /**
  * Return true if the prefix of "ch" is "ignorable". Here, "ignorable" means
- * that "ch" has only one digit and separater characters. The one digit is
- * assumed to be trunk prefix.
+ * that "ch" has only one digit and separator characters. The one digit is
+ * assumed to be the trunk prefix.
  */
 static bool checkPrefixIsIgnorable(const char* ch, int i) {
     bool trunk_prefix_was_read = false;
@@ -304,7 +304,7 @@
     int ccc_a = tryGetCountryCallingCode(a, len_a, &tmp_a, &tmp_len_a, accept_thailand_case);
     int ccc_b = tryGetCountryCallingCode(b, len_b, &tmp_b, &tmp_len_b, accept_thailand_case);
     bool both_have_ccc = false;
-    bool ok_to_ignore_prefix = true;
+    bool may_ignore_prefix = true;
     bool trunk_prefix_is_omitted_a = false;
     bool trunk_prefix_is_omitted_b = false;
     if (ccc_a >= 0 && ccc_b >= 0) {
@@ -314,12 +314,12 @@
         }
         // When both have ccc, do not ignore trunk prefix. Without this,
         // "+81123123" becomes same as "+810123123" (+81 == Japan)
-        ok_to_ignore_prefix = false;
+        may_ignore_prefix = false;
         both_have_ccc = true;
     } else if (ccc_a < 0 && ccc_b < 0) {
         // When both do not have ccc, do not ignore trunk prefix. Without this,
         // "123123" becomes same as "0123123"
-        ok_to_ignore_prefix = false;
+        may_ignore_prefix = false;
     } else {
         if (ccc_a < 0) {
             tryGetTrunkPrefixOmittedStr(a, len_a, &tmp_a, &tmp_len_a);
@@ -364,9 +364,9 @@
         }
     }
 
-    if (ok_to_ignore_prefix) {
-        if ((trunk_prefix_is_omitted_a && i_a >= 0) ||
-            !checkPrefixIsIgnorable(a, i_a)) {
+    if (may_ignore_prefix) {
+        bool trunk_prefix_ignorable_a = checkPrefixIsIgnorable(a, i_a);
+        if ((trunk_prefix_is_omitted_a && i_a >= 0) || !trunk_prefix_ignorable_a) {
             if (accept_thailand_case) {
                 // Maybe the code handling the special case for Thailand makes the
                 // result garbled, so disable the code and try again.
@@ -381,18 +381,31 @@
             } else {
                 return false;
             }
+        } else if (trunk_prefix_ignorable_a && trunk_prefix_is_omitted_b) {
+            bool cmp_prefixes = i_a == 0 && isDialable(a[i_a]);
+            if (cmp_prefixes && org_b[i_a] != a[i_a]) {
+                // Unmatched trunk prefix
+                return false;
+            }
         }
-        if ((trunk_prefix_is_omitted_b && i_b >= 0) ||
-            !checkPrefixIsIgnorable(b, i_b)) {
+
+        bool trunk_prefix_ignorable_b = checkPrefixIsIgnorable(b, i_b);
+        if ((trunk_prefix_is_omitted_b && i_b >= 0) || !trunk_prefix_ignorable_b) {
             if (accept_thailand_case) {
                 return phone_number_compare_inter(org_a, org_b, false);
             } else {
                 return false;
             }
+        } else if (trunk_prefix_ignorable_b && trunk_prefix_is_omitted_a) {
+            bool cmp_prefixes = i_b == 0 && isDialable(b[i_b]);
+            if (cmp_prefixes && org_a[i_b] != b[i_b]) {
+                // Unmatched trunk prefix
+                return false;
+            }
         }
     } else {
         // In the US, 1-650-555-1234 must be equal to 650-555-1234,
-        // while 090-1234-1234 must not be equalt to 90-1234-1234 in Japan.
+        // while 090-1234-1234 must not be equal to 90-1234-1234 in Japan.
         // This request exists just in US (with 1 trunk (NDD) prefix).
         // In addition, "011 11 7005554141" must not equal to "+17005554141",
         // while "011 1 7005554141" must equal to "+17005554141"
diff --git a/android/PhoneNumberUtilsTest.cpp b/android/PhoneNumberUtilsTest.cpp
index beb9c82..ce90c0a 100644
--- a/android/PhoneNumberUtilsTest.cpp
+++ b/android/PhoneNumberUtilsTest.cpp
@@ -32,25 +32,33 @@
 
 using namespace android;
 
-TEST(PhoneNumberUtils, phone_number_compare_strict) {
+
+TEST(PhoneNumberUtils, compareStrictNullOrEmpty) {
     EXPECT_TRUE(phone_number_compare_strict(NULL, NULL));
     EXPECT_TRUE(phone_number_compare_strict("", NULL));
     EXPECT_TRUE(phone_number_compare_strict(NULL, ""));
     EXPECT_TRUE(phone_number_compare_strict("", ""));
+}
 
+TEST(PhoneNumberUtils, compareStrictDigitsSame) {
     EXPECT_TRUE(phone_number_compare_strict("999", "999"));
     EXPECT_TRUE(phone_number_compare_strict("119", "119"));
+}
 
+TEST(PhoneNumberUtils, compareStrictDigitsDifferent) {
     EXPECT_FALSE(phone_number_compare_strict("123456789", "923456789"));
     EXPECT_FALSE(phone_number_compare_strict("123456789", "123456781"));
     EXPECT_FALSE(phone_number_compare_strict("123456789", "1234567890"));
     EXPECT_FALSE(phone_number_compare_strict("123456789", "0123456789"));
+}
 
-    // Google, Inc.
+TEST(PhoneNumberUtils, compareStrictGoogle) {
     EXPECT_TRUE(phone_number_compare_strict("650-253-0000", "6502530000"));
     EXPECT_TRUE(phone_number_compare_strict("650-253-0000", "650 253 0000"));
     EXPECT_TRUE(phone_number_compare_strict("650 253 0000", "6502530000"));
+}
 
+TEST(PhoneNumberUtils, compareStrictTrunkPrefixUs) {
     // trunk (NDD) prefix must be properly handled in US
     EXPECT_TRUE(phone_number_compare_strict("650-253-0000", "1-650-253-0000"));
     EXPECT_TRUE(phone_number_compare_strict("650-253-0000", "   1-650-253-0000"));
@@ -61,70 +69,129 @@
     EXPECT_TRUE(phone_number_compare_strict("+1 650-253-0000", "6502530000"));
     EXPECT_TRUE(phone_number_compare_strict("001 650-253-0000", "6502530000"));
     EXPECT_TRUE(phone_number_compare_strict("0111 650-253-0000", "6502530000"));
+}
 
-    // Country code is different.
+TEST(PhoneNumberUtils, compareStrictDifferentCountryCode) {
     EXPECT_FALSE(phone_number_compare_strict("+19012345678", "+819012345678"));
+}
 
-    // Russian trunk digit
-    EXPECT_TRUE(phone_number_compare_strict("+79161234567", "89161234567"));
-
-    // French trunk digit
-    EXPECT_TRUE(phone_number_compare_strict("+33123456789", "0123456789"));
-
-    // Trunk digit for city codes in the Netherlands
+TEST(PhoneNumberUtils, compareStrictTrunkJapan) {
     EXPECT_TRUE(phone_number_compare_strict("+31771234567", "0771234567"));
-
-    // Japanese dial
     EXPECT_TRUE(phone_number_compare_strict("090-1234-5678", "+819012345678"));
     EXPECT_TRUE(phone_number_compare_strict("090(1234)5678", "+819012345678"));
     EXPECT_TRUE(phone_number_compare_strict("090-1234-5678", "+81-90-1234-5678"));
 
+    EXPECT_TRUE(phone_number_compare_strict("+819012345678", "090-1234-5678"));
+    EXPECT_TRUE(phone_number_compare_strict("+819012345678", "090(1234)5678"));
+    EXPECT_TRUE(phone_number_compare_strict("+81-90-1234-5678", "090-1234-5678"));
+}
+
+TEST(PhoneNumberUtils, compareStrictTrunkRussia) {
+    EXPECT_TRUE(phone_number_compare_strict("+79161234567", "89161234567"));
+}
+
+TEST(PhoneNumberUtils, compareStrictTrunkFrance) {
+    EXPECT_TRUE(phone_number_compare_strict("+33123456789", "0123456789"));
+}
+
+TEST(PhoneNumberUtils, compareStrictTrunkNetherlandsCities) {
+    EXPECT_TRUE(phone_number_compare_strict("+31771234567", "0771234567"));
+}
+
+// TODO: Two digit trunk prefixes are not handled
+//TEST(PhoneNumberUtils, compareStrictTrunkHungary) {
+//  EXPECT_TRUE(phone_number_compare_strict("+36 1 234 5678", "06 1234-5678"));
+//}
+
+// TODO: Two digit trunk prefixes are not handled
+//TEST(PhoneNumberUtils, compareStrictTrunkMexico) {
+//  EXPECT_TRUE(phone_number_compare_strict("+52 55 1234 5678", "01 55 1234 5678"));
+//}
+
+// TODO: Two digit trunk prefixes are not handled
+//TEST(PhoneNumberUtils, compareStrictTrunkMongolia) {
+//  EXPECT_TRUE(phone_number_compare_strict("+976 1 123 4567", "01 1 23 4567"));
+//  EXPECT_TRUE(phone_number_compare_strict("+976 2 234 5678", "02 2 34 5678"));
+//}
+
+TEST(PhoneNumberUtils, compareStrictTrunkIgnoreJapan) {
     // Trunk prefix must not be ignored in Japan
     EXPECT_FALSE(phone_number_compare_strict("090-1234-5678", "90-1234-5678"));
-
     EXPECT_FALSE(phone_number_compare_strict("090-1234-5678", "080-1234-5678"));
     EXPECT_FALSE(phone_number_compare_strict("090-1234-5678", "190-1234-5678"));
     EXPECT_FALSE(phone_number_compare_strict("090-1234-5678", "890-1234-5678"));
+    EXPECT_FALSE(phone_number_compare_strict("080-1234-5678", "+819012345678"));
     EXPECT_FALSE(phone_number_compare_strict("+81-90-1234-5678", "+81-090-1234-5678"));
+}
 
+TEST(PhoneNumberUtils, compareStrictInternationalNational) {
     EXPECT_TRUE(phone_number_compare_strict("+593(800)123-1234", "8001231234"));
+}
 
-    // Two continuous 0 at the beginieng of the phone string should not be
+TEST(PhoneNumberUtils, compareStrictTwoContinuousZeros) {
+    // Two continuous 0 at the begining of the phone string should not be
     // treated as trunk prefix.
     EXPECT_FALSE(phone_number_compare_strict("008001231234", "8001231234"));
+}
 
+TEST(PhoneNumberUtils, compareStrictCallerIdThailandUs) {
     // Test broken caller ID seen on call from Thailand to the US
     EXPECT_TRUE(phone_number_compare_strict("+66811234567", "166811234567"));
-
     // Confirm that the bug found before does not re-appear.
     EXPECT_FALSE(phone_number_compare_strict("080-1234-5678", "+819012345678"));
     EXPECT_TRUE(phone_number_compare_strict("650-000-3456", "16500003456"));
     EXPECT_TRUE(phone_number_compare_strict("011 1 7005554141", "+17005554141"));
     EXPECT_FALSE(phone_number_compare_strict("011 11 7005554141", "+17005554141"));
     EXPECT_FALSE(phone_number_compare_strict("+44 207 792 3490", "00 207 792 3490"));
+}
+
+TEST(PhoneNumberUtils, compareStrictNamp1661) {
     // This is not related to Thailand case. NAMP "1" + region code "661".
     EXPECT_TRUE(phone_number_compare_strict("16610001234", "6610001234"));
+}
 
+TEST(PhoneNumberUtils, compareStrictAlphaDifferent) {
     // We also need to compare two alpha addresses to make sure two different strings
     // aren't treated as the same addresses. This is relevant to SMS as SMS sender may
     // contain all alpha chars.
     EXPECT_FALSE(phone_number_compare_strict("abcd", "bcde"));
+}
 
+TEST(PhoneNumberUtils, compareStrictAlphaNumericSame) {
     // in the U.S. people often use alpha in the phone number to easily remember it
     // (e.g. 800-flowers would be dialed as 800-356-9377). Since we accept this form of
     // phone number in Contacts and others, we should make sure the comparison method
     // handle them.
     EXPECT_TRUE(phone_number_compare_strict("1-800-flowers", "800-flowers"));
+}
 
-    // TODO: we currently do not support this comparison. It maybe nice to support this
-    // TODO: in the future.
-    // EXPECT_TRUE("1-800-flowers", "1-800-356-9377")
-
+TEST(PhoneNumberUtils, compareStrictAlphaNumericDifferent) {
     EXPECT_FALSE(phone_number_compare_strict("1-800-flowers", "1-800-abcdefg"));
+}
 
+// TODO: we currently do not support this comparison.
+// TODO: It maybe be nice to support this in the future.
+//TEST(PhoneNumberUtils, compareStrictLettersToDigits) {
+//  EXPECT_TRUE("1-800-flowers", "1-800-356-9377")
+//}
+
+TEST(PhoneNumberUtils, compareStrictWrongPrefix) {
     // Currently we cannot get this test through (Japanese trunk prefix is 0,
     // but there is no sensible way to know it now (as of 2009-6-12)...
-    // EXPECT_FALSE("290-1234-5678", "+819012345678");
+    // EXPECT_FALSE(phone_number_compare_strict("290-1234-5678", "+819012345678"));
+    // EXPECT_FALSE(phone_number_compare_strict("+819012345678", "290-1234-5678"));
+
+    // USA
+    EXPECT_FALSE(phone_number_compare_strict("550-450-3605", "+14504503605"));
+
+    EXPECT_FALSE(phone_number_compare_strict("550-450-3605", "+15404503605"));
+    EXPECT_FALSE(phone_number_compare_strict("550-450-3605", "+15514503605"));
+    EXPECT_FALSE(phone_number_compare_strict("5504503605", "+14504503605"));
+
+    EXPECT_FALSE(phone_number_compare_strict("+14504503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_strict("+15404503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_strict("+15514503605", "550-450-3605"));
+    EXPECT_FALSE(phone_number_compare_strict("+14504503605", "5504503605"));
 }
 
 TEST(PhoneNumberUtils, phone_number_stripped_reversed_inter) {