diff --git a/test/Core.Test/Utilities/HtmlEncodingStringConverterTests.cs b/test/Core.Test/Utilities/HtmlEncodingStringConverterTests.cs
new file mode 100644
index 0000000000..0d0cffb79d
--- /dev/null
+++ b/test/Core.Test/Utilities/HtmlEncodingStringConverterTests.cs
@@ -0,0 +1,89 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Bit.Core.Utilities;
+using Xunit;
+
+namespace Bit.Core.Test.Utilities;
+
+public class HtmlEncodingStringConverterTests
+{
+    [Fact]
+    public void Serialize_WhenEncodedValueIsNotNull_SerializesHtmlEncodedString()
+    {
+        // Arrange
+        var obj = new HtmlEncodedString
+        {
+            EncodedValue = "This is <b>bold</b>",
+            NonEncodedValue = "This is <b>bold</b>"
+        };
+
+        // This is necessary to prevent the serializer from double encoding the string
+        var serializerOptions = new JsonSerializerOptions
+        {
+            Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+        };
+
+        // Act
+        var jsonString = JsonSerializer.Serialize(obj, serializerOptions);
+
+        // Assert
+        const string expected = "{\"EncodedValue\":\"This is <b>bold</b>\",\"NonEncodedValue\":\"This is <b>bold</b>\"}";
+        Assert.Equal(expected, jsonString);
+    }
+
+    [Fact]
+    public void Serialize_WhenEncodedValueIsNull_SerializesNull()
+    {
+        // Arrange
+        var obj = new HtmlEncodedString
+        {
+            EncodedValue = null,
+            NonEncodedValue = null
+        };
+
+        // Act
+        var jsonString = JsonSerializer.Serialize(obj);
+
+        // Assert
+        const string expected = "{\"EncodedValue\":null,\"NonEncodedValue\":null}";
+        Assert.Equal(expected, jsonString);
+    }
+
+    [Fact]
+    public void Deserialize_WhenJsonContainsHtmlEncodedString_ReturnsDecodedString()
+    {
+        // Arrange
+        const string json = "{\"EncodedValue\":\"This is <b>bold</b>\",\"NonEncodedValue\":\"This is <b>bold</b>\"}";
+
+        // Act
+        var obj = JsonSerializer.Deserialize<HtmlEncodedString>(json);
+
+        // Assert
+        const string expectedEncodedValue = "This is &lt;b&gt;bold&lt;/b&gt;";
+        const string expectedNonEncodedValue = "This is <b>bold</b>";
+        Assert.Equal(expectedEncodedValue, obj.EncodedValue);
+        Assert.Equal(expectedNonEncodedValue, obj.NonEncodedValue);
+    }
+
+    [Fact]
+    public void Deserialize_WhenJsonContainsNull_ReturnsNull()
+    {
+        // Arrange
+        const string json = "{\"EncodedValue\":null,\"NonEncodedValue\":null}";
+
+        // Act
+        var obj = JsonSerializer.Deserialize<HtmlEncodedString>(json);
+
+        // Assert
+        Assert.Null(obj.EncodedValue);
+        Assert.Null(obj.NonEncodedValue);
+    }
+}
+
+public class HtmlEncodedString
+{
+    [JsonConverter(typeof(HtmlEncodingStringConverter))]
+    public string EncodedValue { get; set; }
+
+    public string NonEncodedValue { get; set; }
+}