diff --git a/commcheck-api/cli/.vscode/launch.json b/commcheck-api/cli/.vscode/launch.json
index 814dc57..75d1237 100644
--- a/commcheck-api/cli/.vscode/launch.json
+++ b/commcheck-api/cli/.vscode/launch.json
@@ -11,7 +11,7 @@
             "preLaunchTask": "build",
             // If you have changed target frameworks, make sure to update the program path.
             "program": "${workspaceFolder}/bin/Debug/net8.0/cli.dll",
-            "args": [],
+            "args": ["--dob=2020-01-01", "--rfr=DEA"],
             "cwd": "${workspaceFolder}",
             // For more information about the 'console' field, see https://aka.ms/VSCode-CS-LaunchJson-Console
             "console": "internalConsole",
diff --git a/commcheck-api/cli/Program.cs b/commcheck-api/cli/Program.cs
index 1a4116a..f193f47 100644
--- a/commcheck-api/cli/Program.cs
+++ b/commcheck-api/cli/Program.cs
@@ -8,25 +8,42 @@
 using Microsoft.Extensions.Logging;
 
 
-var fileOption = new Option<DateOnly>(
+var dobOption = new Option<DateOnly>(
     name: "--dob",
-    description: "Date of birth (yyyy-mm-dd)");
+    description: "Date of birth (yyyy-mm-dd)")
+{
+    IsRequired = true
+};
+
+var baseUrl = new Option<Uri>(
+    name: "--host",
+    description: "Base url. defaults to https://commchecks.azurewebsites.net");
+baseUrl.SetDefaultValue(new Uri("https://commchecks.azurewebsites.net"));
+
+var rfrCode = new Option<string>(
+    name: "--rfr",
+    description: "Reason for removal code")
+    {
+        IsRequired = true
+    };
 
 var rootCommand = new RootCommand("Commcheck cli v1");
-rootCommand.AddOption(fileOption);
+rootCommand.AddOption(dobOption);
+rootCommand.AddOption(baseUrl);
+rootCommand.AddOption(rfrCode);
 
-rootCommand.SetHandler(async (dob) => 
+rootCommand.SetHandler(async (dob, url, rfr) => 
     { 
         var builder = Host.CreateApplicationBuilder(args);
         builder.Services.AddHttpClient<CommsCheck>(options=>
         {
-            options.BaseAddress = new Uri("https://commchecks.azurewebsites.net");
+            options.BaseAddress = url;
         });
         var host = builder.Build();
         var check = host.Services.GetRequiredService<CommsCheck>();
-        var content = await check.Check(dob);
+        var content = await check.Check(dob, Enum.Parse<ReasonForRemovals>(rfr));
     },
-    fileOption);
+    dobOption, baseUrl, rfrCode);
 
 return await rootCommand.InvokeAsync(args);
 
@@ -34,13 +51,15 @@
 
 public class CommsCheck(HttpClient client, ILogger<CommsCheck> logger)
 {
-    public async Task<CommsCheckAnswerResponseDto>  Check(DateOnly dob)
+    public async Task<CommsCheckAnswerResponseDto>  Check(
+        DateOnly dob, 
+        ReasonForRemovals rfr)
     {
         var response = await client.PostAsJsonAsync(
             "check", 
             CommsCheckQuestionRequestDto.DobOnly(
                 dob,
-                ReasonForRemovals.None));
+                rfr));
 
        
         var location = response.Headers.Location;
diff --git a/commcheck-api/src/rules.json b/commcheck-api/src/rules.json
index 2d83016..24f0f3b 100644
--- a/commcheck-api/src/rules.json
+++ b/commcheck-api/src/rules.json
@@ -129,6 +129,13 @@
         "ErrorMessage": "",
         "Enabled": false,
         "Expression": "true"
+      },
+      {
+        "RuleName": "Block ZZ99",
+        "SuccessEvent": "Explicit Postal Block 99: Block ZZ99",
+        "ErrorMessage": "",
+        "Enabled": true,
+        "Expression": "item.PostCode.IsZZ99 == true"
       }
     ]
   },
diff --git a/commcheck-api/src/src/Api/CommsCheckAnswerResponseDto.cs b/commcheck-api/src/src/Api/CommsCheckAnswerResponseDto.cs
index 17cd01f..8ff8f9c 100644
--- a/commcheck-api/src/src/Api/CommsCheckAnswerResponseDto.cs
+++ b/commcheck-api/src/src/Api/CommsCheckAnswerResponseDto.cs
@@ -21,3 +21,4 @@ public static CommsCheckAnswerResponseDto FromCommsCheckAnswer(CommsCheckAnswer
             );  
     }
 }
+
diff --git a/commcheck-api/src/src/Api/CommsCheckQuestionRequestDto.cs b/commcheck-api/src/src/Api/CommsCheckQuestionRequestDto.cs
index 6dbee44..cd61660 100644
--- a/commcheck-api/src/src/Api/CommsCheckQuestionRequestDto.cs
+++ b/commcheck-api/src/src/Api/CommsCheckQuestionRequestDto.cs
@@ -1,7 +1,51 @@
 namespace CommsCheck;
 
+using System.Globalization;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 
+ public class PostalCodeJsonConverter : JsonConverter<PostalCode>
+    {
+        public override PostalCode Read(
+            ref Utf8JsonReader reader,
+            Type typeToConvert,
+            JsonSerializerOptions options) =>
+                PostalCode.Parse(reader.GetString()!);
+
+        public override void Write(
+            Utf8JsonWriter writer,
+            PostalCode postCodeValue,
+            JsonSerializerOptions options) =>
+                writer.WriteStringValue(postCodeValue.PostCode);
+    }
+
+public readonly record struct PostalCode 
+{
+    public string PostCode {get;init;}
+
+    public bool IsZZ99 => PostCode!=null && PostCode.StartsWith("ZZ99");
+
+    [JsonConstructor]
+    public PostalCode(string postCode)
+    {
+        ArgumentNullException.ThrowIfNullOrWhiteSpace(postCode, nameof(postCode));
+        PostCode = ParsePostcodeString(postCode);
+    }
+
+    public static PostalCode Parse(string postCode)
+    {
+        return new PostalCode(postCode);
+    }
+
+    private static string ParsePostcodeString(string postcode)
+    {
+        ArgumentNullException.ThrowIfNullOrWhiteSpace(postcode, nameof(postcode));
+        return postcode.ToUpper().Replace(" ", "");
+    }
+
+    public static PostalCode Empty =>  new PostalCode();
+}
+
 public readonly record struct CommsCheckQuestionRequestDto(
     DateOnly DateOfBirth, 
     DateOnly DateOfSmsMostRecentUpdate,
@@ -10,7 +54,8 @@ public readonly record struct CommsCheckQuestionRequestDto(
     DateOnly DateOfPostalMostRecentUpdate,
     DateOnly DateOfReasonForRemovalMostRecentUpdate,
     DeathStatus? DeathStatusValue,
-    ReasonForRemovals? RfR)
+    ReasonForRemovals? RfR,
+    PostalCode PostCode)
 {
 
     public static CommsCheckQuestionRequestDto DobOnly(
@@ -24,5 +69,6 @@ public static CommsCheckQuestionRequestDto DobOnly(
             DateOnly.MinValue,
             DateOnly.MinValue,
             DeathStatus.None,
-            reasonForRemoval);
+            reasonForRemoval,
+            PostalCode.Empty);
 }
diff --git a/commcheck-api/src/src/CommsCheck/CommsCheckItem.cs b/commcheck-api/src/src/CommsCheck/CommsCheckItem.cs
index 6062f82..dfaf0fa 100644
--- a/commcheck-api/src/src/CommsCheck/CommsCheckItem.cs
+++ b/commcheck-api/src/src/CommsCheck/CommsCheckItem.cs
@@ -9,6 +9,7 @@ public readonly record struct CommsCheckItem(
     DateOnly DateOfReasonForRemovalMostRecentUpdate,
     IReasonForRemoval ReasonForRemoval,
     IDeathStatus DeathStatus,
+    PostalCode PostCode,
     CommsCheckQuestionRequestDtoCopy CopyOfSource)
 {
     public int DaysOld =>
@@ -56,6 +57,7 @@ public CommsCheckItem FromDtoRelativeToToday(CommsCheckQuestionRequestDto dto)
         dto.DateOfReasonForRemovalMostRecentUpdate,
         IReasonForRemoval.FromEnum(dto.RfR),
         IDeathStatus.FromEnum(dto.DeathStatusValue),
+        dto.PostCode,
         CommsCheckQuestionRequestDtoCopy.FromDto(dto));
     }
 }
@@ -67,7 +69,8 @@ public readonly record struct CommsCheckQuestionRequestDtoCopy(DateOnly DateOfBi
     DateOnly DateOfPostalMostRecentUpdate,
     DateOnly DateOfReasonForRemovalMostRecentUpdate,
     DeathStatus? DeathStatusValue,
-    ReasonForRemovals? RfR
+    ReasonForRemovals? RfR,
+    PostalCode PostCode
     )
 {
     public static CommsCheckQuestionRequestDtoCopy FromDto(CommsCheckQuestionRequestDto dto) =>
@@ -79,7 +82,8 @@ public static CommsCheckQuestionRequestDtoCopy FromDto(CommsCheckQuestionRequest
                 dto.DateOfPostalMostRecentUpdate,
                 dto.DateOfReasonForRemovalMostRecentUpdate,
                 dto.DeathStatusValue,
-                 dto.RfR);
+                 dto.RfR,
+                 dto.PostCode);
 
     public CommsCheckQuestionRequestDto ToDto() => 
              new CommsCheckQuestionRequestDto(
@@ -90,5 +94,6 @@ public CommsCheckQuestionRequestDto ToDto() =>
                 DateOfPostalMostRecentUpdate,
                 DateOfReasonForRemovalMostRecentUpdate,
                 DeathStatusValue,
-                RfR);
+                RfR,
+                PostCode);
 }
\ No newline at end of file
diff --git a/commcheck-api/src/src/CommsCheck/CommsCheckRulesEngine/RulesEngineRulesLoader.cs b/commcheck-api/src/src/CommsCheck/CommsCheckRulesEngine/RulesEngineRulesLoader.cs
index f8f0670..6a0175a 100644
--- a/commcheck-api/src/src/CommsCheck/CommsCheckRulesEngine/RulesEngineRulesLoader.cs
+++ b/commcheck-api/src/src/CommsCheck/CommsCheckRulesEngine/RulesEngineRulesLoader.cs
@@ -6,7 +6,6 @@ namespace CommsCheck;
 using System.Text;
 using Microsoft.Extensions.Caching.Distributed;
 using Microsoft.Extensions.Options;
-using Newtonsoft.Json.Converters;
 using RulesEngine;
 using RulesEngine.Models;
 
diff --git a/commcheck-api/src/src/Extensions/CommsCheckOptions.cs b/commcheck-api/src/src/Extensions/CommsCheckOptions.cs
index 7994566..d158758 100644
--- a/commcheck-api/src/src/Extensions/CommsCheckOptions.cs
+++ b/commcheck-api/src/src/Extensions/CommsCheckOptions.cs
@@ -24,6 +24,7 @@ public CommsCheckOptions AddJsonConfig()
             options.SerializerOptions.WriteIndented = true;
             options.SerializerOptions.IncludeFields = true;
             options.SerializerOptions.Converters.Add(new JsonStringEnumConverter());
+            options.SerializerOptions.Converters.Add(new PostalCodeJsonConverter());
             options.SerializerOptions.PropertyNameCaseInsensitive = true;
         });
 
@@ -31,6 +32,7 @@ public CommsCheckOptions AddJsonConfig()
         {
             options.JsonSerializerOptions.PropertyNameCaseInsensitive = true;
             options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
+            options.JsonSerializerOptions.Converters.Add(new PostalCodeJsonConverter());
         });
         return this;
     }
diff --git a/commcheck-api/src/src/Extensions/SwaggerGenExtensions.cs b/commcheck-api/src/src/Extensions/SwaggerGenExtensions.cs
index 49cbaef..95f18da 100644
--- a/commcheck-api/src/src/Extensions/SwaggerGenExtensions.cs
+++ b/commcheck-api/src/src/Extensions/SwaggerGenExtensions.cs
@@ -15,6 +15,12 @@ public static SwaggerGenOptions AddDateAndEnumFormatters(
             Format = "date"
         });
 
+        options.MapType<PostalCode>(() => new OpenApiSchema()
+        {
+            Type = "string"
+        });
+
+
         var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
         var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
         options.IncludeXmlComments(xmlPath);