diff --git a/neon_users_service/exceptions.py b/neon_users_service/exceptions.py
index af6e472..8f660ea 100644
--- a/neon_users_service/exceptions.py
+++ b/neon_users_service/exceptions.py
@@ -8,4 +8,10 @@ class UserExistsError(Exception):
 class UserNotFoundError(Exception):
     """
     Raised when trying to look up a user that does not exist.
+    """
+
+
+class ConfigurationError(KeyError):
+    """
+    Raised when service configuration is not valid.
     """
\ No newline at end of file
diff --git a/neon_users_service/service.py b/neon_users_service/service.py
index fafaec2..c5568a9 100644
--- a/neon_users_service/service.py
+++ b/neon_users_service/service.py
@@ -1,12 +1,20 @@
+import hashlib
+import re
+from copy import copy
 from typing import Optional
 from ovos_config import Configuration
 from neon_users_service.databases import UserDatabase
+from neon_users_service.exceptions import ConfigurationError
+from neon_users_service.models import User
 
 
 class NeonUsersService:
     def __init__(self, config: Optional[dict] = None):
         self.config = config or Configuration().get("neon_users_service", {})
         self.database = self.init_database()
+        if not self.database:
+            raise ConfigurationError(f"`{self.config.get('module')}` is not a "
+                                     f"valid database module.")
 
     def init_database(self) -> UserDatabase:
         module = self.config.get("module")
@@ -16,3 +24,35 @@ def init_database(self) -> UserDatabase:
             return SQLiteUserDatabase(**module_config)
         # Other supported databases may be added here
 
+    @staticmethod
+    def _ensure_hashed(password: str) -> str:
+        """
+        Generate the sha-256 hash for an input password to be stored in the
+        database. If the password is already a valid hash string, it will be
+        returned with no changes.
+        @param password: Input password string to be hashed
+        @retruns: A hexadecimal string representation of the sha-256 hash
+        """
+        if re.compile(r"^[a-f0-9]{64}$").match(password):
+            password_hash = password
+        else:
+            password_hash = hashlib.sha256(password.encode("utf-8")).hexdigest()
+        return password_hash
+
+    def create_user(self, user: User) -> User:
+        """
+        Helper to create a new user. Includes a check that the input password
+        hash is valid, replacing string passwords with hashes as necessary.
+        @param user: The user to be created
+        @returns: The user as added to the database
+        """
+        # Create a copy to prevent modifying the input object
+        user = copy(user)
+        user.password_hash = self._ensure_hashed(user.password_hash)
+        return self.database.create_user(user)
+
+    def shutdown(self):
+        """
+        Shutdown the service
+        """
+        self.database.shutdown()
diff --git a/tests/test_service.py b/tests/test_service.py
new file mode 100644
index 0000000..2b21156
--- /dev/null
+++ b/tests/test_service.py
@@ -0,0 +1,50 @@
+import hashlib
+import os
+from unittest import TestCase
+from os.path import join, dirname, isfile
+
+from neon_users_service.databases import UserDatabase
+from neon_users_service.databases.sqlite import SQLiteUserDatabase
+from neon_users_service.exceptions import ConfigurationError
+from neon_users_service.models import User
+from neon_users_service.service import NeonUsersService
+
+
+class TestUsersService(TestCase):
+    test_db_path = join(dirname(__file__), 'test_db.sqlite')
+    test_config = {"module": "sqlite",
+                   "sqlite": {"db_path": test_db_path}}
+
+    def setUp(self):
+        if isfile(self.test_db_path):
+            os.remove(self.test_db_path)
+
+    def test_create_service(self):
+        # Create with default config
+        service = NeonUsersService()
+        self.assertIsNotNone(service.config)
+        self.assertIsInstance(service.database, UserDatabase)
+        service.shutdown()
+
+        # Create with valid passed configuration
+        service = NeonUsersService(self.test_config)
+        self.assertIsInstance(service.database, SQLiteUserDatabase)
+        self.assertTrue(isfile(self.test_db_path))
+        service.shutdown()
+
+        # Create with invalid configuration
+        with self.assertRaises(ConfigurationError):
+            NeonUsersService({"module": None})
+
+    def test_create_user(self):
+        service = NeonUsersService(self.test_config)
+        string_password = "super secret password"
+        hashed_password = hashlib.sha256(string_password.encode()).hexdigest()
+        user_1 = service.create_user(User(username="user_1",
+                                          password_hash=hashed_password))
+        input_user_2 = User(username="user_2", password_hash=string_password)
+        user_2 = service.create_user(input_user_2)
+        self.assertEqual(user_1.password_hash, hashed_password)
+        self.assertEqual(user_2.password_hash, hashed_password)
+        # The input object should not be modified
+        self.assertNotEqual(user_2, input_user_2)