diff --git a/app/routes/reports.py b/app/routes/reports.py
index 5dd4624..d4ddad2 100644
--- a/app/routes/reports.py
+++ b/app/routes/reports.py
@@ -744,7 +744,7 @@ def export_project_excel():
         if project.id not in projects_map:
             projects_map[project.id] = {
                 'name': project.name,
-                'client': project.client.name if project.client else '',
+                'client': project.client if project.client else '',
                 'total_hours': 0,
                 'billable_hours': 0,
                 'hourly_rate': float(project.hourly_rate) if project.hourly_rate else 0,
diff --git a/app/templates/projects/view.html b/app/templates/projects/view.html
index a887b82..c8874e2 100644
--- a/app/templates/projects/view.html
+++ b/app/templates/projects/view.html
@@ -10,7 +10,7 @@
             <span class="inline-flex items-center px-2 py-0.5 rounded text-[10px] font-semibold tracking-wide uppercase bg-gray-200 text-gray-800 dark:bg-gray-700 dark:text-gray-200" title="{{ _('Project Code') }}">{{ project.code_display }}</span>
             {% endif %}
         </h1>
-        <p class="text-text-muted-light dark:text-text-muted-dark">{{ project.client.name }}</p>
+        <p class="text-text-muted-light dark:text-text-muted-dark">{{ project.client }}</p>
     </div>
     {% if current_user.is_admin or has_any_permission(['edit_projects', 'archive_projects']) %}
     <div class="flex gap-2 flex-wrap">
diff --git a/app/utils/excel_export.py b/app/utils/excel_export.py
index 6d3905f..c1aeb8a 100644
--- a/app/utils/excel_export.py
+++ b/app/utils/excel_export.py
@@ -54,7 +54,7 @@ def create_time_entries_excel(entries, filename_prefix='timetracker_export'):
             entry.id,
             entry.user.display_name if entry.user else 'Unknown',
             entry.project.name if entry.project else 'N/A',
-            entry.project.client.name if (entry.project and entry.project.client) else 'N/A',
+            entry.project.client if (entry.project and entry.project.client) else 'N/A',
             entry.task.name if entry.task else 'N/A',
             entry.start_time.isoformat() if entry.start_time else '',
             entry.end_time.isoformat() if entry.end_time else '',
diff --git a/tests/test_excel_export.py b/tests/test_excel_export.py
new file mode 100644
index 0000000..29a970a
--- /dev/null
+++ b/tests/test_excel_export.py
@@ -0,0 +1,144 @@
+"""
+Tests for Excel export functionality
+"""
+import pytest
+from datetime import datetime, timedelta
+from app.models import TimeEntry, Task
+
+
+@pytest.mark.unit
+@pytest.mark.routes
+def test_create_time_entries_excel_with_client(app, user, project, test_client):
+    """Test that Excel export handles project.client correctly as a string property"""
+    from app.utils.excel_export import create_time_entries_excel
+    
+    # Create a time entry with project that has a client
+    start_time = datetime.utcnow() - timedelta(hours=2)
+    end_time = datetime.utcnow()
+    
+    entry = TimeEntry(
+        user_id=user.id,
+        project_id=project.id,
+        start_time=start_time,
+        end_time=end_time,
+        notes='Test entry for Excel export',
+        tags='test,export',
+        source='manual',
+        billable=True
+    )
+    
+    # Calculate duration manually since we're not going through the full commit cycle
+    entry.duration_seconds = (end_time - start_time).total_seconds()
+    
+    # Test that project.client is a string property, not an object
+    assert hasattr(project, 'client')
+    assert isinstance(project.client, str)
+    assert project.client == test_client.name
+    
+    # Test Excel export function
+    output, filename = create_time_entries_excel([entry])
+    
+    # Verify the output was created successfully
+    assert output is not None
+    assert filename is not None
+    assert filename.endswith('.xlsx')
+    
+    # Verify the file content can be read
+    output.seek(0)
+    content = output.read()
+    assert len(content) > 0
+
+
+@pytest.mark.unit
+@pytest.mark.routes  
+def test_create_time_entries_excel_with_task(app, user, project, task):
+    """Test that Excel export handles entries with tasks correctly"""
+    from app.utils.excel_export import create_time_entries_excel
+    
+    # Create a time entry with a task
+    start_time = datetime.utcnow() - timedelta(hours=1)
+    end_time = datetime.utcnow()
+    
+    entry = TimeEntry(
+        user_id=user.id,
+        project_id=project.id,
+        task_id=task.id,
+        start_time=start_time,
+        end_time=end_time,
+        notes='Test entry with task',
+        billable=True
+    )
+    
+    # Calculate duration
+    entry.duration_seconds = (end_time - start_time).total_seconds()
+    
+    # Test Excel export function
+    output, filename = create_time_entries_excel([entry])
+    
+    # Verify the output was created successfully
+    assert output is not None
+    assert filename is not None
+    
+    # Verify the file content can be read
+    output.seek(0)
+    content = output.read()
+    assert len(content) > 0
+
+
+@pytest.mark.unit
+@pytest.mark.routes
+def test_create_time_entries_excel_multiple_entries(app, multiple_time_entries):
+    """Test Excel export with multiple time entries"""
+    from app.utils.excel_export import create_time_entries_excel
+    
+    # Test Excel export function with multiple entries
+    output, filename = create_time_entries_excel(multiple_time_entries)
+    
+    # Verify the output was created successfully
+    assert output is not None
+    assert filename is not None
+    
+    # Verify the file content can be read
+    output.seek(0)
+    content = output.read()
+    assert len(content) > 0
+
+
+@pytest.mark.unit  
+@pytest.mark.routes
+def test_project_report_excel_export(app, time_entry):
+    """Test project report Excel export with project.client"""
+    from app.utils.excel_export import create_project_report_excel
+    
+    # Create project data structure
+    project = time_entry.project
+    projects_data = [{
+        'name': project.name,
+        'client': project.client,  # Should be a string
+        'total_hours': 8.0,
+        'billable_hours': 7.5,
+        'hourly_rate': 75.00,
+        'billable_amount': 562.50,
+        'total_costs': 0,
+        'total_value': 562.50
+    }]
+    
+    # Test that project.client is a string
+    assert isinstance(project.client, str)
+    
+    # Test Excel export function
+    output, filename = create_project_report_excel(
+        projects_data, 
+        start_date='2024-01-01', 
+        end_date='2024-12-31'
+    )
+    
+    # Verify the output was created successfully
+    assert output is not None
+    assert filename is not None
+    
+    # Verify the file content can be read
+    output.seek(0)
+    content = output.read()
+    assert len(content) > 0
+