diff --git a/PKHeX.Core/Legality/Checks.cs b/PKHeX.Core/Legality/Checks.cs
index 0fc90e94f..f2f1a2859 100644
--- a/PKHeX.Core/Legality/Checks.cs
+++ b/PKHeX.Core/Legality/Checks.cs
@@ -181,14 +181,10 @@ private void VerifyNickname()
             if (!Encounter.Valid)
                 return;
 
-            if (pkm.Format <= 6 && pkm.Language > 8)
+            int maxLanguageID = Legal.GetMaxLanguageID(Info.Generation);
+            if (pkm.Language == 6 || pkm.Language > maxLanguageID)
             {
-                AddLine(Severity.Indeterminate, V4, CheckIdentifier.Language);
-                return;
-            }
-            if (pkm.Format <= 7 && pkm.Language > 10)
-            {
-                AddLine(Severity.Indeterminate, V5, CheckIdentifier.Language);
+                AddLine(Severity.Indeterminate, string.Format(V5, "<=" + maxLanguageID, pkm.Language), CheckIdentifier.Language);
                 return;
             }
 
@@ -321,7 +317,11 @@ private void VerifyNicknameTrade()
                 return;
             }
             else if (3 <= Info.Generation && Info.Generation <= 5)
-            { 
+            {
+                // Trades for JPN games have language ID of 0, not 1.
+                if (pkm.BW && pkm.Format == 5 && pkm.Language == 1)
+                    AddLine(Severity.Invalid, string.Format(V5, 0, 1), CheckIdentifier.Language);
+
                 // Suppressing temporarily
                 return;
             }
diff --git a/PKHeX.Core/Legality/Core.cs b/PKHeX.Core/Legality/Core.cs
index 417989733..b684efe56 100644
--- a/PKHeX.Core/Legality/Core.cs
+++ b/PKHeX.Core/Legality/Core.cs
@@ -1101,6 +1101,23 @@ internal static IEnumerable<int> GetFutureGenEvolutions(int generation)
             }
         }
 
+        internal static int GetMaxLanguageID(int generation)
+        {
+            switch (generation)
+            {
+                case 1:
+                case 2:
+                case 7:
+                    return 10; // VC -> Gen7
+                case 3:
+                    return 7; // 1-7 except 6
+                case 4:
+                case 5:
+                case 6:
+                    return 8;
+            }
+            return -1;
+        }
         private static bool[] GetReleasedHeldItems(int generation)
         {
             switch (generation)
diff --git a/PKHeX.Core/Legality/Encounters/EncounterGenerator.cs b/PKHeX.Core/Legality/Encounters/EncounterGenerator.cs
index 6073364fc..b270edd7a 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterGenerator.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterGenerator.cs
@@ -883,7 +883,9 @@ private static IEnumerable<EncounterTrade> GetValidEncounterTrades(PKM pkm, Game
             }
 
             int lang = pkm.Language;
-            if (lang == 0 || lang == 6)
+            if (lang == 6) // invalid language
+                yield break;
+            if (lang == 0 && (pkm.Format != 5 || !pkm.BW)) // Japanese trades in BW have no language ID
                 yield break;
 
             int lvl = GetMinLevelEncounter(pkm);
diff --git a/PKHeX.Core/Legality/LegalityCheckStrings.cs b/PKHeX.Core/Legality/LegalityCheckStrings.cs
index bbf495227..ac9519f2c 100644
--- a/PKHeX.Core/Legality/LegalityCheckStrings.cs
+++ b/PKHeX.Core/Legality/LegalityCheckStrings.cs
@@ -108,9 +108,8 @@ public static class LegalityCheckStrings
         public static string V11 {get; set;} = "Ingame Trade OT and Nickname have not been altered."; // Valid
         public static string V1 {get; set;} = "Nickname too long."; // Invalid
         public static string V2 {get; set;} = "Nickname is empty."; // Invalid
-        public static string V4 {get; set;} = "Language ID > 8."; // Invalid
-        public static string V5 {get; set;} = "Language ID > 10."; // Invalid
-        public static string V222 { get; set; } = "Cannot be given this Nickname."; // Invalid
+        public static string V5 {get; set;} = "Language ID should be {0}, not {1}."; // Invalid
+        public static string V222 {get; set;} = "Cannot be given this Nickname."; // Invalid
         public static string V3 {get; set;} = "Species index invalid for Nickname comparison."; // Invalid
         public static string V20 {get; set;} = "Nickname does not match species name."; // Invalid
         public static string V13 {get; set;} = "Egg name does not match language Egg name."; // Invalid
diff --git a/PKHeX.Core/PKM/PK5.cs b/PKHeX.Core/PKM/PK5.cs
index 5f10d4e15..face551bb 100644
--- a/PKHeX.Core/PKM/PK5.cs
+++ b/PKHeX.Core/PKM/PK5.cs
@@ -310,7 +310,7 @@ public PK6 ConvertToPK6()
                 else pk6.AbilityNumber = Gen5 ? 1 << (int)(PID >> 16 & 1) : 1 << (int)(PID & 1);
             }
             pk6.Markings = Markings;
-            pk6.Language = Language;
+            pk6.Language = Math.Max(1, Language); // Hacked or Bad IngameTrade (Japanese B/W)
 
             pk6.CNT_Cool = CNT_Cool;
             pk6.CNT_Beauty = CNT_Beauty;
diff --git a/PKHeX.Core/PKM/PKM.cs b/PKHeX.Core/PKM/PKM.cs
index 6281a7005..d19930e23 100644
--- a/PKHeX.Core/PKM/PKM.cs
+++ b/PKHeX.Core/PKM/PKM.cs
@@ -292,6 +292,7 @@ private byte[] Write()
         public bool FRLG => Version == (int)GameVersion.FR || Version == (int)GameVersion.LG;
         public bool Pt => (int)GameVersion.Pt == Version;
         public bool HGSS => Version == (int)GameVersion.HG || Version == (int)GameVersion.SS;
+        public bool BW => Version == (int)GameVersion.B || Version == (int)GameVersion.W;
         public bool B2W2 => Version == (int)GameVersion.B2 || Version == (int)GameVersion.W2;
         public bool XY => Version == (int)GameVersion.X || Version == (int)GameVersion.Y;
         public bool AO => Version == (int)GameVersion.AS || Version == (int)GameVersion.OR;
diff --git a/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt b/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
index 32c2fff06..7df60feb4 100644
--- a/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
+++ b/PKHeX.Core/Resources/text/en/LegalityCheckStrings_en.txt
@@ -69,8 +69,7 @@ V19 = Nickname matches demo language name.
 V11 = Ingame Trade OT and Nickname have not been altered.
 V1 = Nickname too long.
 V2 = Nickname is empty.
-V4 = Language ID > 8.
-V5 = Language ID > 10.
+V5 = Language ID should be {0}, not {1}.
 V222 = Cannot be given this Nickname.
 V3 = Species index invalid for Nickname comparison.
 V20 = Nickname does not match species name.
diff --git a/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt b/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
index 7be28db52..5aa47669b 100644
--- a/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
+++ b/PKHeX.Core/Resources/text/ko/LegalityCheckStrings_ko.txt
@@ -69,8 +69,7 @@ V19 = 이름이 언어별 데모 이름과 일치합니다.
 V11 = 게임 내 교환의 어버이와 이름이 달라졌습니다.
 V1 = 이름이 너무 깁니다.
 V2 = 이름이 비어 있습니다.
-V4 = 언어 ID가 8을 초과합니다.
-V5 = 언어 ID가 10을 초과합니다.
+V5 = 언어 ID should be {0}, not {1}.
 V222 = 이 이름은 사용할 수 없습니다.
 V3 = 이름 비교에 사용할 포켓몬 종류 인덱스가 잘못되었습니다.
 V20 = 이름이 포켓몬 종류와 일치하지 않습니다.
diff --git a/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt b/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
index 3975de2e9..54fcd380e 100644
--- a/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
+++ b/PKHeX.Core/Resources/text/zh/LegalityCheckStrings_zh.txt
@@ -69,8 +69,7 @@ V19 = 昵称与体验版语言一致。
 V11 = 游戏内连接交换的初训家和昵称未被修改。
 V1 = 昵称太长。
 V2 = 昵称为空。
-V4 = 语言ID > 8。
-V5 = 语言ID > 10。
+V5 = 语言ID should be {0}, not {1}。
 V222 = 无法给宝可梦取中文昵称。
 V3 = 宝可梦种类无法用于昵称对比
 V20 = 昵称与种类名不一致。