diff --git a/src/test/java/uk/gov/companieshouse/api/filinghistory/utils/TransactionKindResultTest.java b/src/test/java/uk/gov/companieshouse/api/filinghistory/utils/TransactionKindResultTest.java
new file mode 100644
index 0000000..e60afbd
--- /dev/null
+++ b/src/test/java/uk/gov/companieshouse/api/filinghistory/utils/TransactionKindResultTest.java
@@ -0,0 +1,92 @@
+package uk.gov.companieshouse.api.filinghistory.utils;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+class TransactionKindResultTest {
+
+    @Test
+    void constructorShouldSetFields() {
+        TransactionKind kind = TransactionKind.TOP_LEVEL;
+
+        TransactionKindResult result = new TransactionKindResult("encoded-id", kind);
+
+        assertEquals("encoded-id", result.getEncodedId());
+        assertEquals(kind, result.getKind());
+    }
+
+    @Test
+    void settersShouldUpdateFields() {
+        TransactionKindResult result = new TransactionKindResult(null, null);
+
+        result.setEncodedId("new-id");
+        result.setKind(TransactionKind.TOP_LEVEL);
+
+        assertEquals("new-id", result.getEncodedId());
+        assertEquals(TransactionKind.TOP_LEVEL, result.getKind());
+    }
+
+    @Test
+    void equalsShouldReturnTrueForSameValues() {
+        TransactionKindResult first = new TransactionKindResult("id1", TransactionKind.TOP_LEVEL);
+
+        TransactionKindResult second = new TransactionKindResult("id1", TransactionKind.TOP_LEVEL);
+
+        assertEquals(first, second);
+        assertEquals(first.hashCode(), second.hashCode());
+    }
+
+    @Test
+    void equalsShouldReturnFalseForDifferentEncodedId() {
+        TransactionKindResult first = new TransactionKindResult("id1", TransactionKind.TOP_LEVEL);
+
+        TransactionKindResult second = new TransactionKindResult("id2", TransactionKind.TOP_LEVEL);
+
+        assertNotEquals(first, second);
+        assertNotEquals(first.hashCode(), second.hashCode());
+    }
+
+    @Test
+    void equalsShouldReturnFalseForDifferentKind() {
+        TransactionKindResult first = new TransactionKindResult("id1", TransactionKind.TOP_LEVEL);
+
+        TransactionKindResult second = new TransactionKindResult("id1", TransactionKind.ASSOCIATED_FILING);
+
+        assertNotEquals(first, second);
+        assertNotEquals(first.hashCode(), second.hashCode());
+    }
+
+    @Test
+    void equalsShouldReturnFalseForDifferentObjectType() {
+        TransactionKindResult result = new TransactionKindResult("id1", TransactionKind.ANNOTATION);
+
+        assertNotEquals("not-a-TransactionKindResult", result);
+    }
+
+    @Test
+    void equalsShouldHandleNullFields() {
+        TransactionKindResult first = new TransactionKindResult(null, null);
+
+        TransactionKindResult second = new TransactionKindResult(null, null);
+
+        assertEquals(first, second);
+    }
+
+    @Test
+    void hashCodeShouldHandleNullValues() {
+        TransactionKindResult result = new TransactionKindResult(null, null);
+
+        int hashcode = result.hashCode();
+        assertNotEquals(0, hashcode);
+    }
+
+    @Test
+    void hashCodeShouldHandleNonNullValues() {
+        TransactionKindResult result = new TransactionKindResult("id1", TransactionKind.RESOLUTION);
+
+        int hashcode = result.hashCode();
+        assertNotEquals(0, hashcode);
+    }
+}
diff --git a/src/test/java/uk/gov/companieshouse/api/serialization/LocalDateDeserializerTest.java b/src/test/java/uk/gov/companieshouse/api/serialization/LocalDateDeserializerTest.java
index ae5866b..56fab8b 100644
--- a/src/test/java/uk/gov/companieshouse/api/serialization/LocalDateDeserializerTest.java
+++ b/src/test/java/uk/gov/companieshouse/api/serialization/LocalDateDeserializerTest.java
@@ -1,10 +1,12 @@
 package uk.gov.companieshouse.api.serialization;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.time.LocalDate;
 
-import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -15,6 +17,8 @@
 
 class LocalDateDeserializerTest {
 
+    private static final String DESERIALISATION_FALIED_EXCEPTION_MESSAGE = "Deserialization failed.";
+    private static final String DATE_FIELD_MISSING_OR_NULL = "$date field is missing or null";
     private LocalDateDeserializer deserializer;
 
     private ObjectMapper mapper;
@@ -31,7 +35,7 @@ void dateShouldDeserialize() {
         String jsonTestString = "{\"date\":{\"$date\": \"2023-01-09T00:00:00Z\"}}";
 
         LocalDate returnedDate = deserialize(jsonTestString);
-        Assertions.assertEquals(LocalDate.of(2023, 1, 9), returnedDate);
+        assertEquals(LocalDate.of(2023, 1, 9), returnedDate);
     }
 
     @Test
@@ -39,7 +43,7 @@ void longStringReturnsLong() {
         String jsonTestString = "{\"date\":{\"$date\": {\"$numberLong\":\"-1431388800000\"}}}";
 
         LocalDate returnedDate = deserialize(jsonTestString);
-        Assertions.assertEquals(LocalDate.of(1924, 8, 23), returnedDate);
+        assertEquals(LocalDate.of(1924, 8, 23), returnedDate);
     }
 
     @Test
@@ -52,19 +56,39 @@ void nullStringReturnsError() {
     void invalidStringReturnsError() {
         String jsonTestString = "{\"date\":{\"$date\": \"NotADate\"}}}";
 
-        assertThrows(java.time.format.DateTimeParseException.class, () -> deserialize(jsonTestString));
+        assertException(DESERIALISATION_FALIED_EXCEPTION_MESSAGE, jsonTestString);
     }
 
     @Test
     void missingDateFieldReturnsError() {
         String jsonTestString = "{\"date\":{}}";
-        assertThrows(BadRequestException.class, () -> deserialize(jsonTestString));
+
+        assertException(DATE_FIELD_MISSING_OR_NULL, jsonTestString);
     }
 
     @Test
     void nullDateFieldReturnsError() {
         String jsonTestString = "{\"date\":{\"$date\":null}}";
-        assertThrows(BadRequestException.class, () -> deserialize(jsonTestString));
+
+        assertException(DATE_FIELD_MISSING_OR_NULL, jsonTestString);
+    }
+
+    @Test
+    void invalidDateShouldReturnError() {
+
+        JsonParser parser = mock(JsonParser.class);
+        when(parser.readValueAsTree())
+                .thenThrow(new RuntimeException("Invalid JSON"));
+        BadRequestException exception = assertThrows(BadRequestException.class, () -> deserializer.deserialize(parser, null));
+
+        assertEquals(DESERIALISATION_FALIED_EXCEPTION_MESSAGE, exception.getMessage());
+    }
+
+    @Test
+    void invalidNumberLongReturnError() {
+        String jsonTestString = "{\"date\":{\"$date\": {\"$numberLong\":\"not-a-number\"}}}";
+
+        assertException(DESERIALISATION_FALIED_EXCEPTION_MESSAGE, jsonTestString);
     }
 
     private LocalDate deserialize(String jsonString) {
@@ -76,13 +100,14 @@ private LocalDate deserialize(String jsonString) {
             // Pass null for DeserializationContext as it's not used in the deserializer
             return deserializer.deserialize(parser, null);
         } catch (Exception e) {
-            // Unwrap if it's a RuntimeException wrapping another exception
-            if (e instanceof RuntimeException && e.getCause() != null) {
-                throw (RuntimeException) e.getCause();
-            }
-            // Otherwise, rethrow as is
             throw e;
         }
     }
 
+    private void assertException(String expectedMessage, String jsonTestString) {
+        BadRequestException exception = assertThrows(BadRequestException.class, () -> deserialize(jsonTestString));
+
+        assertEquals(expectedMessage, exception.getMessage());
+    }
+
 }
\ No newline at end of file