diff --git a/hiero-enterprise-base/src/test/java/com/openelements/hiero/base/test/FileClientImplTest.java b/hiero-enterprise-base/src/test/java/com/openelements/hiero/base/test/FileClientImplTest.java
index e48f1fc..9c4b4a2 100644
--- a/hiero-enterprise-base/src/test/java/com/openelements/hiero/base/test/FileClientImplTest.java
+++ b/hiero-enterprise-base/src/test/java/com/openelements/hiero/base/test/FileClientImplTest.java
@@ -11,6 +11,8 @@
 import com.openelements.hiero.base.protocol.FileAppendResult;
 import com.openelements.hiero.base.protocol.FileInfoRequest;
 import com.openelements.hiero.base.protocol.FileInfoResponse;
+import com.openelements.hiero.base.protocol.FileContentsRequest;
+import com.openelements.hiero.base.protocol.FileContentsResponse;
 import com.openelements.hiero.base.protocol.ProtocolLayerClient;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
@@ -263,4 +265,54 @@ void testGetFileSizeThrowsExceptionForNullId() {
         );
         Assertions.assertTrue(exception.getMessage().contains(message));
     }
+
+    @Test
+    void testReadFile() throws HieroException {
+        // mock
+        final FileContentsResponse fileContentsResponse = Mockito.mock(FileContentsResponse.class);
+        final byte[] content = "Hello Hiero!".getBytes();
+
+        // given
+        final FileId fileId = FileId.fromString("1.2.3");
+
+        when(protocolLayerClient.executeFileContentsQuery(any(FileContentsRequest.class)))
+                .thenReturn(fileContentsResponse);
+        when(fileContentsResponse.contents()).thenReturn(content);
+
+        final byte[] result = fileClientImpl.readFile(fileId);
+
+        verify(protocolLayerClient, times(1))
+                .executeFileContentsQuery(any(FileContentsRequest.class));
+        verify(fileContentsResponse, times(1)).contents();
+
+        Assertions.assertArrayEquals(content, result);
+    }
+
+    @Test
+    void testReadFileThrowsExceptionForInvalidId() throws HieroException {
+        // given
+        final FileId fileId = FileId.fromString("1.2.3");
+        final String message = "Failed to read file with fileId " + fileId;
+
+        when(protocolLayerClient.executeFileContentsQuery(any(FileContentsRequest.class)))
+                .thenThrow(new HieroException("Failed to execute query"));
+
+        final HieroException exception = Assertions.assertThrows(
+                HieroException.class, () -> fileClientImpl.readFile(fileId)
+        );
+
+        Assertions.assertTrue(exception.getMessage().contains(message));
+    }
+
+    @Test
+    void testReadFileThrowsExceptionForNullValue() {
+        final String message = "fileId must not be null";
+        final FileId fileId = null;
+
+        final NullPointerException exception = Assertions.assertThrows(
+                NullPointerException.class, () -> fileClientImpl.readFile(fileId)
+        );
+
+        Assertions.assertTrue(exception.getMessage().contains(message));
+    }
 }
diff --git a/hiero-enterprise-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java b/hiero-enterprise-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
index 3289c70..5b0b6b7 100644
--- a/hiero-enterprise-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
+++ b/hiero-enterprise-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
@@ -96,7 +96,7 @@ void testCreateFileThrowExceptionIfExpirationTimeBeforeNow() {
     @Test
     void testReadFileByFileId() throws Exception {
         //given
-        final byte[] contents = "Hello, Hedera!".getBytes();
+        final byte[] contents = "Hello, Hiero!".getBytes();
         final FileId fileId = fileClient.createFile(contents);
 
         //when
@@ -109,7 +109,7 @@ void testReadFileByFileId() throws Exception {
     @Test
     void testReadFileByStringId() throws Exception {
         //given
-        final byte[] contents = "Hello, Hedera!".getBytes();
+        final byte[] contents = "Hello, Hiero!".getBytes();
         final String fileId = fileClient.createFile(contents).toString();
 
         //when
@@ -122,7 +122,7 @@ void testReadFileByStringId() throws Exception {
     @Test
     void testReadLargeFileByStringId() throws Exception {
         //given
-        final byte[] contents = IntStream.range(0, 500).mapToObj(i -> "Hello, Hedera!")
+        final byte[] contents = IntStream.range(0, 500).mapToObj(i -> "Hello, Hiero!")
                 .reduce((a, b) -> a + b)
                 .get()
                 .getBytes();
@@ -135,6 +135,12 @@ void testReadLargeFileByStringId() throws Exception {
         Assertions.assertArrayEquals(contents, readContents);
     }
 
+    @Test
+    void testReadFileThrowsExceptionForInvalidId() {
+        final FileId fileId = FileId.fromString("1.2.3");
+        Assertions.assertThrows(HieroException.class, () -> fileClient.readFile(fileId));
+    }
+
     @Test
     void testDeleteFileByFileId() throws Exception {
         //given