diff --git a/src/World.Net.UnitTests/Countries/ChristmasIslandTest.cs b/src/World.Net.UnitTests/Countries/ChristmasIslandTest.cs
new file mode 100644
index 0000000..804615d
--- /dev/null
+++ b/src/World.Net.UnitTests/Countries/ChristmasIslandTest.cs
@@ -0,0 +1,39 @@
+namespace World.Net.UnitTests.Countries;
+
+public sealed class ChristmasIslandTest
+{
+    private const string CHRISTMAS_ISLAND_COUNTRY_NAME = "Christmas Island";
+    private const string CHRISTMAS_ISLAND_NATIVE_NAME = "Christmas Island";
+    private const string CHRISTMAS_ISLAND_CAPITAL = "Flying Fish Cove";
+    private const string CHRISTMAS_ISLAND_OFFICIAL_NAME = "Territory of Christmas Island";
+    private const string CHRISTMAS_ISLAND_ISO2_CODE = "CX";
+    private const string CHRISTMAS_ISLAND_ISO3_CODE = "CXR";
+    private const int CHRISTMAS_ISLAND_NUMERIC_CODE = 162;
+    private const string CHRISTMAS_ISLAND_CALLING_CODE = "+61";
+    private static readonly string[] VALID_STATE_TYPES = { };
+
+    [Fact]
+    public void GetCountry_ReturnsCorrectInformation_ForChristmasIsland()
+    {
+        // Arrange
+        CountryIdentifier existingCountryId = CountryIdentifier.ChristmasIsland;
+
+        // Act
+        var country = CountryProvider.GetCountry(existingCountryId);
+
+        // Assert
+        Assert.NotNull(country);
+        Assert.Equal(existingCountryId, country.Id);
+        Assert.Equal(CHRISTMAS_ISLAND_COUNTRY_NAME, country.Name);
+        Assert.Equal(CHRISTMAS_ISLAND_OFFICIAL_NAME, country.OfficialName);
+        Assert.Equal(CHRISTMAS_ISLAND_NATIVE_NAME, country.NativeName);
+        Assert.Equal(CHRISTMAS_ISLAND_CAPITAL, country.Capital);
+        Assert.Equal(CHRISTMAS_ISLAND_NUMERIC_CODE, country.NumericCode);
+        Assert.Equal(CHRISTMAS_ISLAND_ISO2_CODE, country.ISO2Code);
+        Assert.Equal(CHRISTMAS_ISLAND_ISO3_CODE, country.ISO3Code);
+        Assert.Equal(CHRISTMAS_ISLAND_CALLING_CODE, country.CallingCode);
+        Assert.NotNull(country.States);
+        Assert.Empty(country.States);
+        Assert.All(country.States, state => Assert.Contains(state.Type, VALID_STATE_TYPES));
+    }
+}
diff --git a/src/World.Net.UnitTests/Countries/CocosKeelingIslandsTest.cs b/src/World.Net.UnitTests/Countries/CocosKeelingIslandsTest.cs
new file mode 100644
index 0000000..adc1c97
--- /dev/null
+++ b/src/World.Net.UnitTests/Countries/CocosKeelingIslandsTest.cs
@@ -0,0 +1,40 @@
+namespace World.Net.UnitTests.Countries;
+
+public sealed class CocosKeelingIslandsTest
+{
+    private const string COCOS_COUNTRY_NAME = "Cocos (Keeling) Islands";
+    private const string COCOS_NATIVE_NAME = "Pulu Kokos (Malay)";
+    private const string COCOS_CAPITAL = "West Island";
+    private const string COCOS_OFFICIAL_NAME = "Territory of Cocos (Keeling) Islands";
+    private const string COCOS_ISO2_CODE = "CC";
+    private const string COCOS_ISO3_CODE = "CCK";
+    private const int COCOS_NUMERIC_CODE = 166;
+    private const string COCOS_CALLING_CODE = "+61";
+    private const int COCOS_STATE_COUNT = 2;
+    private static readonly string[] VALID_STATE_TYPES = { "Island" };
+
+    [Fact]
+    public void GetCountry_ReturnsCorrectInformation_ForCocosKeelingIslands()
+    {
+        // Arrange
+        CountryIdentifier existingCountryId = CountryIdentifier.CocosKeelingIslands;
+
+        // Act
+        var country = CountryProvider.GetCountry(existingCountryId);
+
+        // Assert
+        Assert.NotNull(country);
+        Assert.Equal(existingCountryId, country.Id);
+        Assert.Equal(COCOS_COUNTRY_NAME, country.Name);
+        Assert.Equal(COCOS_OFFICIAL_NAME, country.OfficialName);
+        Assert.Equal(COCOS_NATIVE_NAME, country.NativeName);
+        Assert.Equal(COCOS_CAPITAL, country.Capital);
+        Assert.Equal(COCOS_NUMERIC_CODE, country.NumericCode);
+        Assert.Equal(COCOS_ISO2_CODE, country.ISO2Code);
+        Assert.Equal(COCOS_ISO3_CODE, country.ISO3Code);
+        Assert.Equal(COCOS_CALLING_CODE, country.CallingCode);
+        Assert.NotNull(country.States);
+        Assert.Equal(COCOS_STATE_COUNT, country.States.Count());
+        Assert.All(country.States, state => Assert.Contains(state.Type, VALID_STATE_TYPES));
+    }
+}
diff --git a/src/World.Net.UnitTests/Countries/ColombiaTest.cs b/src/World.Net.UnitTests/Countries/ColombiaTest.cs
new file mode 100644
index 0000000..5ef0f12
--- /dev/null
+++ b/src/World.Net.UnitTests/Countries/ColombiaTest.cs
@@ -0,0 +1,40 @@
+namespace World.Net.UnitTests.Countries;
+
+public sealed class ColombiaTest
+{
+    private const string COLOMBIA_COUNTRY_NAME = "Colombia";
+    private const string COLOMBIA_NATIVE_NAME = "Colombia";
+    private const string COLOMBIA_CAPITAL = "Bogotá";
+    private const string COLOMBIA_OFFICIAL_NAME = "Republic of Colombia";
+    private const string COLOMBIA_ISO2_CODE = "CO";
+    private const string COLOMBIA_ISO3_CODE = "COL";
+    private const int COLOMBIA_NUMERIC_CODE = 170;
+    private const string COLOMBIA_CALLING_CODE = "+57";
+    private const int COLOMBIA_STATE_COUNT = 32;
+    private static readonly string[] VALID_STATE_TYPES = { "Department", "Capital District" };
+
+    [Fact]
+    public void GetCountry_ReturnsCorrectInformation_ForColombia()
+    {
+        // Arrange
+        CountryIdentifier existingCountryId = CountryIdentifier.Colombia;
+
+        // Act
+        var country = CountryProvider.GetCountry(existingCountryId);
+
+        // Assert
+        Assert.NotNull(country);
+        Assert.Equal(existingCountryId, country.Id);
+        Assert.Equal(COLOMBIA_COUNTRY_NAME, country.Name);
+        Assert.Equal(COLOMBIA_OFFICIAL_NAME, country.OfficialName);
+        Assert.Equal(COLOMBIA_NATIVE_NAME, country.NativeName);
+        Assert.Equal(COLOMBIA_CAPITAL, country.Capital);
+        Assert.Equal(COLOMBIA_NUMERIC_CODE, country.NumericCode);
+        Assert.Equal(COLOMBIA_ISO2_CODE, country.ISO2Code);
+        Assert.Equal(COLOMBIA_ISO3_CODE, country.ISO3Code);
+        Assert.Equal(COLOMBIA_CALLING_CODE, country.CallingCode);
+        Assert.NotNull(country.States);
+        Assert.Equal(COLOMBIA_STATE_COUNT, country.States.Count());
+        Assert.All(country.States, state => Assert.Contains(state.Type, VALID_STATE_TYPES));
+    }
+}
diff --git a/src/World.Net.UnitTests/Countries/ComorosTest.cs b/src/World.Net.UnitTests/Countries/ComorosTest.cs
new file mode 100644
index 0000000..a1f82e6
--- /dev/null
+++ b/src/World.Net.UnitTests/Countries/ComorosTest.cs
@@ -0,0 +1,40 @@
+namespace World.Net.UnitTests.Countries;
+
+public sealed class ComorosTest
+{
+    private const string COMOROS_COUNTRY_NAME = "Comoros";
+    private const string COMOROS_NATIVE_NAME = "Komori";
+    private const string COMOROS_CAPITAL = "Moroni";
+    private const string COMOROS_OFFICIAL_NAME = "Union of the Comoros";
+    private const string COMOROS_ISO2_CODE = "KM";
+    private const string COMOROS_ISO3_CODE = "COM";
+    private const int COMOROS_NUMERIC_CODE = 174;
+    private const string COMOROS_CALLING_CODE = "+269";
+    private const int COMOROS_STATE_COUNT = 3;
+    private static readonly string[] VALID_STATE_TYPES = { "Autonomous Island" };
+    
+    [Fact]
+    public void GetCountry_ReturnsCorrectInformation_ForComoros()
+    {
+        // Arrange
+        CountryIdentifier existingCountryId = CountryIdentifier.Comoros;
+
+        // Act
+        var country = CountryProvider.GetCountry(existingCountryId);
+
+        // Assert
+        Assert.NotNull(country);
+        Assert.Equal(existingCountryId, country.Id);
+        Assert.Equal(COMOROS_COUNTRY_NAME, country.Name);
+        Assert.Equal(COMOROS_OFFICIAL_NAME, country.OfficialName);
+        Assert.Equal(COMOROS_NATIVE_NAME, country.NativeName);
+        Assert.Equal(COMOROS_CAPITAL, country.Capital);
+        Assert.Equal(COMOROS_NUMERIC_CODE, country.NumericCode);
+        Assert.Equal(COMOROS_ISO2_CODE, country.ISO2Code);
+        Assert.Equal(COMOROS_ISO3_CODE, country.ISO3Code);
+        Assert.Equal(COMOROS_CALLING_CODE, country.CallingCode);
+        Assert.NotNull(country.States);
+        Assert.Equal(COMOROS_STATE_COUNT, country.States.Count());
+        Assert.All(country.States, state => Assert.Contains(state.Type, VALID_STATE_TYPES));
+    }
+}
diff --git a/src/World.Net/Countries/ChristmasIsland.cs b/src/World.Net/Countries/ChristmasIsland.cs
new file mode 100644
index 0000000..7f3d412
--- /dev/null
+++ b/src/World.Net/Countries/ChristmasIsland.cs
@@ -0,0 +1,37 @@
+namespace World.Net.Countries;
+
+internal sealed class ChristmasIsland : ICountry
+{
+    //<inheritdoc/>
+    public CountryIdentifier Id => CountryIdentifier.ChristmasIsland;
+
+    //<inheritdoc/>
+    public string Name { get; } = "Christmas Island";
+
+    //<inheritdoc/>
+    public string OfficialName { get; } = "Territory of Christmas Island";
+
+    //<inheritdoc/>
+    public string NativeName => "Christmas Island";
+
+    //<inheritdoc/>
+    public string Capital { get; } = "Flying Fish Cove";
+
+    //<inheritdoc/>
+    public int NumericCode { get; } = 162;
+
+    //<inheritdoc/>
+    public string ISO2Code { get; } = "CX";
+
+    //<inheritdoc/>
+    public string ISO3Code { get; } = "CXR";
+
+    //<inheritdoc/>
+    public string CallingCode { get; } = "+61";
+
+    //<inheritdoc/>
+    public IEnumerable<State> States =>
+    [
+        
+    ];
+}
diff --git a/src/World.Net/Countries/CocosKeelingIslands.cs b/src/World.Net/Countries/CocosKeelingIslands.cs
new file mode 100644
index 0000000..4690f91
--- /dev/null
+++ b/src/World.Net/Countries/CocosKeelingIslands.cs
@@ -0,0 +1,38 @@
+namespace World.Net.Countries;
+
+internal sealed class CocosKeelingIslands : ICountry
+{
+    //<inheritdoc/>
+    public CountryIdentifier Id => CountryIdentifier.CocosKeelingIslands;
+
+    //<inheritdoc/>
+    public string Name { get; } = "Cocos (Keeling) Islands";
+
+    //<inheritdoc/>
+    public string OfficialName { get; } = "Territory of Cocos (Keeling) Islands";
+
+    //<inheritdoc/>
+    public string NativeName => "Pulu Kokos (Malay)";
+
+    //<inheritdoc/>
+    public string Capital { get; } = "West Island";
+
+    //<inheritdoc/>
+    public int NumericCode { get; } = 166;
+
+    //<inheritdoc/>
+    public string ISO2Code { get; } = "CC";
+
+    //<inheritdoc/>
+    public string ISO3Code { get; } = "CCK";
+
+    //<inheritdoc/>
+    public string CallingCode { get; } = "+61";
+
+    //<inheritdoc/>
+    public IEnumerable<State> States =>
+    [
+        new("West Island", "CC-WI", "Island"),
+        new("Home Island", "CC-HI", "Island")
+    ];
+}
diff --git a/src/World.Net/Countries/Colombia.cs b/src/World.Net/Countries/Colombia.cs
new file mode 100644
index 0000000..9467f0d
--- /dev/null
+++ b/src/World.Net/Countries/Colombia.cs
@@ -0,0 +1,68 @@
+namespace World.Net.Countries;
+
+internal sealed class Colombia : ICountry
+{
+    //<inheritdoc/>
+    public CountryIdentifier Id => CountryIdentifier.Colombia;
+
+    //<inheritdoc/>
+    public string Name { get; } = "Colombia";
+
+    //<inheritdoc/>
+    public string OfficialName { get; } = "Republic of Colombia";
+
+    //<inheritdoc/>
+    public string NativeName => "Colombia";
+
+    //<inheritdoc/>
+    public string Capital { get; } = "Bogotá";
+
+    //<inheritdoc/>
+    public int NumericCode { get; } = 170;
+
+    //<inheritdoc/>
+    public string ISO2Code { get; } = "CO";
+
+    //<inheritdoc/>
+    public string ISO3Code { get; } = "COL";
+
+    //<inheritdoc/>
+    public string CallingCode { get; } = "+57";
+
+    //<inheritdoc/>
+    public IEnumerable<State> States =>
+    [
+        new("Amazonas", "CO-AMA", "Department"),
+        new("Antioquia", "CO-ANT", "Department"),
+        new("Arauca", "CO-ARA", "Department"),
+        new("Atlántico", "CO-ATL", "Department"),
+        new("Bolívar", "CO-BOL", "Department"),
+        new("Boyacá", "CO-BOY", "Department"),
+        new("Caldas", "CO-CAL", "Department"),
+        new("Caquetá", "CO-CAQ", "Department"),
+        new("Casanare", "CO-CAS", "Department"),
+        new("Cauca", "CO-CAU", "Department"),
+        new("Cesar", "CO-CES", "Department"),
+        new("Chocó", "CO-CHO", "Department"),
+        new("Córdoba", "CO-COR", "Department"),
+        new("Cundinamarca", "CO-CUN", "Department"),
+        new("Guainía", "CO-GUA", "Department"),
+        new("Guaviare", "CO-GUV", "Department"),
+        new("Huila", "CO-HUI", "Department"),
+        new("La Guajira", "CO-LAG", "Department"),
+        new("Magdalena", "CO-MAG", "Department"),
+        new("Meta", "CO-MET", "Department"),
+        new("Nariño", "CO-NAR", "Department"),
+        new("Norte de Santander", "CO-NSA", "Department"),
+        new("Putumayo", "CO-PUT", "Department"),
+        new("Quindío", "CO-QUI", "Department"),
+        new("Risaralda", "CO-RIS", "Department"),
+        new("San Andrés, Providencia and Santa Catalina", "CO-SAP", "Department"),
+        new("Santander", "CO-SAN", "Department"),
+        new("Sucre", "CO-SUC", "Department"),
+        new("Tolima", "CO-TOL", "Department"),
+        new("Valle del Cauca", "CO-VAC", "Department"),
+        new("Vaupés", "CO-VAU", "Department"),
+        new("Vichada", "CO-VIC", "Department")
+    ];
+}
diff --git a/src/World.Net/Countries/Comoros.cs b/src/World.Net/Countries/Comoros.cs
new file mode 100644
index 0000000..2a1d83e
--- /dev/null
+++ b/src/World.Net/Countries/Comoros.cs
@@ -0,0 +1,39 @@
+namespace World.Net.Countries;
+
+internal sealed class Comoros : ICountry
+{
+    //<inheritdoc/>
+    public CountryIdentifier Id => CountryIdentifier.Comoros;
+
+    //<inheritdoc/>
+    public string Name { get; } = "Comoros";
+
+    //<inheritdoc/>
+    public string OfficialName { get; } = "Union of the Comoros";
+
+    //<inheritdoc/>
+    public string NativeName => "Komori";
+
+    //<inheritdoc/>
+    public string Capital { get; } = "Moroni";
+
+    //<inheritdoc/>
+    public int NumericCode { get; } = 174;
+
+    //<inheritdoc/>
+    public string ISO2Code { get; } = "KM";
+
+    //<inheritdoc/>
+    public string ISO3Code { get; } = "COM";
+
+    //<inheritdoc/>
+    public string CallingCode { get; } = "+269";
+
+    //<inheritdoc/>
+    public IEnumerable<State> States =>
+    [
+        new("Anjouan", "KM-A", "Autonomous Island"),
+        new("Grande Comore", "KM-G", "Autonomous Island"),
+        new("Mohéli", "KM-M", "Autonomous Island")
+    ];
+}
diff --git a/src/World.Net/Helpers/CountryInitializer.cs b/src/World.Net/Helpers/CountryInitializer.cs
index cc6cb53..893be47 100644
--- a/src/World.Net/Helpers/CountryInitializer.cs
+++ b/src/World.Net/Helpers/CountryInitializer.cs
@@ -45,7 +45,11 @@ public static Dictionary<CountryIdentifier, ICountry> Initialize()
             { CountryIdentifier.Cambodia, new Cambodia() },
             { CountryIdentifier.Cameroon, new Cameroon() },
             { CountryIdentifier.Canada, new Canada() },
-            { CountryIdentifier.CapeVerde, new CapeVerde() },           
+            { CountryIdentifier.CapeVerde, new CapeVerde() }, 
+            { CountryIdentifier.ChristmasIsland, new ChristmasIsland() },
+            { CountryIdentifier.CocosKeelingIslands, new CocosKeelingIslands() },
+            { CountryIdentifier.Colombia, new Colombia() },
+            { CountryIdentifier.Comoros, new Comoros() },
 
             // Future countries can be added here in the same format.
         };