diff --git a/commands/add.py b/commands/add.py
index 1b1a943..d29b6b3 100644
--- a/commands/add.py
+++ b/commands/add.py
@@ -1,22 +1,9 @@
 """Add task command."""
 
 import json
-from pathlib import Path
 
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_description(description):
-    """Validate task description."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    if not description:
-        raise ValueError("Description cannot be empty")
-    if len(description) > 200:
-        raise ValueError("Description too long (max 200 chars)")
-    return description.strip()
+from utils.paths import get_tasks_file
+from utils.validation import validate_description
 
 
 def add_task(description):
diff --git a/commands/done.py b/commands/done.py
index c9dfd42..ec3c0c4 100644
--- a/commands/done.py
+++ b/commands/done.py
@@ -1,20 +1,9 @@
 """Mark task done command."""
 
 import json
-from pathlib import Path
 
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_task_id(tasks, task_id):
-    """Validate task ID exists."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    if task_id < 1 or task_id > len(tasks):
-        raise ValueError(f"Invalid task ID: {task_id}")
-    return task_id
+from utils.paths import get_tasks_file
+from utils.validation import validate_task_id
 
 
 def mark_done(task_id):
diff --git a/commands/list.py b/commands/list.py
index 714315d..95a01a7 100644
--- a/commands/list.py
+++ b/commands/list.py
@@ -1,27 +1,14 @@
 """List tasks command."""
 
 import json
-from pathlib import Path
 
-
-def get_tasks_file():
-    """Get path to tasks file."""
-    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
-
-
-def validate_task_file():
-    """Validate tasks file exists."""
-    # NOTE: Validation logic scattered here - should be in utils (refactor bounty)
-    tasks_file = get_tasks_file()
-    if not tasks_file.exists():
-        return []
-    return tasks_file
+from utils.paths import get_tasks_file
+from utils.validation import validate_task_file
 
 
 def list_tasks():
     """List all tasks."""
-    # NOTE: No --json flag support yet (feature bounty)
-    tasks_file = validate_task_file()
+    tasks_file = validate_task_file(get_tasks_file())
     if not tasks_file:
         print("No tasks yet!")
         return
@@ -33,5 +20,5 @@ def list_tasks():
         return
 
     for task in tasks:
-        status = "✓" if task["done"] else " "
+        status = "\u2713" if task["done"] else " "
         print(f"[{status}] {task['id']}. {task['description']}")
diff --git a/test_task.py b/test_task.py
index ba98e43..d6824ce 100644
--- a/test_task.py
+++ b/test_task.py
@@ -2,9 +2,22 @@
 
 import json
 import pytest
+import subprocess
 from pathlib import Path
-from commands.add import add_task, validate_description
-from commands.done import validate_task_id
+from commands.add import add_task
+from commands.list import list_tasks
+from commands.done import mark_done
+from utils.validation import validate_description, validate_task_id, validate_task_file
+from utils.paths import get_tasks_file
+
+
+def _patch_tasks_file(monkeypatch, tmp_path):
+    """Patch get_tasks_file in all modules that import it."""
+    target = tmp_path / "tasks.json"
+    monkeypatch.setattr("commands.add.get_tasks_file", lambda: target)
+    monkeypatch.setattr("commands.list.get_tasks_file", lambda: target)
+    monkeypatch.setattr("commands.done.get_tasks_file", lambda: target)
+    return target
 
 
 def test_validate_description():
@@ -28,3 +41,61 @@ def test_validate_task_id():
 
     with pytest.raises(ValueError):
         validate_task_id(tasks, 99)
+
+
+def test_validate_task_file(tmp_path):
+    """Test task file validation."""
+    # Non-existent file returns empty list
+    missing = tmp_path / "nonexistent.json"
+    assert validate_task_file(missing) == []
+
+    # Existing file returns the path
+    existing = tmp_path / "tasks.json"
+    existing.write_text("[]")
+    assert validate_task_file(existing) == existing
+
+
+def test_get_tasks_file():
+    """Test shared path helper returns expected path."""
+    result = get_tasks_file()
+    assert result == Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
+
+
+def test_add_task(capsys, tmp_path, monkeypatch):
+    """Test add command produces correct output."""
+    _patch_tasks_file(monkeypatch, tmp_path)
+    add_task("Test task")
+    output = capsys.readouterr().out.strip()
+    assert "Added task 1: Test task" == output
+
+
+def test_list_empty(capsys, tmp_path, monkeypatch):
+    """Test list command with no tasks."""
+    _patch_tasks_file(monkeypatch, tmp_path)
+    list_tasks()
+    output = capsys.readouterr().out.strip()
+    assert "No tasks yet!" == output
+
+
+def test_list_tasks(capsys, tmp_path, monkeypatch):
+    """Test list command shows tasks."""
+    _patch_tasks_file(monkeypatch, tmp_path)
+    add_task("First task")
+    add_task("Second task")
+    list_tasks()
+    output = capsys.readouterr().out.strip()
+    assert "1. First task" in output
+    assert "2. Second task" in output
+
+
+def test_mark_done(capsys, tmp_path, monkeypatch):
+    """Test done command marks task complete."""
+    _patch_tasks_file(monkeypatch, tmp_path)
+    add_task("Task to complete")
+    mark_done(1)
+    lines = capsys.readouterr().out.strip().split("\n")
+    assert "Marked task 1 as done: Task to complete" == lines[-1]
+
+    # Verify the file was updated
+    tasks = json.loads((tmp_path / "tasks.json").read_text())
+    assert tasks[0]["done"] is True
diff --git a/utils/__init__.py b/utils/__init__.py
new file mode 100644
index 0000000..3857fda
--- /dev/null
+++ b/utils/__init__.py
@@ -0,0 +1 @@
+"""Shared utilities for task CLI."""
diff --git a/utils/paths.py b/utils/paths.py
new file mode 100644
index 0000000..ec29514
--- /dev/null
+++ b/utils/paths.py
@@ -0,0 +1,8 @@
+"""Shared path helpers for task CLI."""
+
+from pathlib import Path
+
+
+def get_tasks_file():
+    """Get path to tasks file."""
+    return Path.home() / ".local" / "share" / "task-cli" / "tasks.json"
diff --git a/utils/validation.py b/utils/validation.py
new file mode 100644
index 0000000..d69157a
--- /dev/null
+++ b/utils/validation.py
@@ -0,0 +1,52 @@
+"""Shared validation functions for task CLI."""
+
+
+def validate_description(description):
+    """Validate task description.
+
+    Args:
+        description: Raw task description string.
+
+    Returns:
+        Stripped description string.
+
+    Raises:
+        ValueError: If description is empty or exceeds 200 characters.
+    """
+    if not description:
+        raise ValueError("Description cannot be empty")
+    if len(description) > 200:
+        raise ValueError("Description too long (max 200 chars)")
+    return description.strip()
+
+
+def validate_task_id(tasks, task_id):
+    """Validate task ID exists in the task list.
+
+    Args:
+        tasks: List of task dicts.
+        task_id: Integer task ID to validate.
+
+    Returns:
+        Validated task ID.
+
+    Raises:
+        ValueError: If task ID is out of range.
+    """
+    if task_id < 1 or task_id > len(tasks):
+        raise ValueError(f"Invalid task ID: {task_id}")
+    return task_id
+
+
+def validate_task_file(tasks_file):
+    """Validate tasks file exists and return it, or empty list if missing.
+
+    Args:
+        tasks_file: Path object to the tasks JSON file.
+
+    Returns:
+        The tasks_file Path if it exists, or an empty list if not.
+    """
+    if not tasks_file.exists():
+        return []
+    return tasks_file