diff --git a/api/src/controllers/UserController.kt b/api/src/controllers/UserController.kt
index 0c69c41..fce3b8e 100644
--- a/api/src/controllers/UserController.kt
+++ b/api/src/controllers/UserController.kt
@@ -2,9 +2,8 @@ package be.vandewalleh.controllers
 
 import be.vandewalleh.auth.SimpleJWT
 import be.vandewalleh.auth.UsernamePasswordCredential
-import be.vandewalleh.entities.User
-import be.vandewalleh.errors.ApiError
-import be.vandewalleh.tables.Users
+import be.vandewalleh.services.UserRegistrationDto
+import be.vandewalleh.services.UserService
 import io.ktor.application.call
 import io.ktor.http.HttpStatusCode
 import io.ktor.locations.Location
@@ -12,37 +11,26 @@ import io.ktor.locations.post
 import io.ktor.request.receive
 import io.ktor.response.respond
 import io.ktor.routing.Routing
-import me.liuwj.ktorm.database.Database
-import me.liuwj.ktorm.dsl.*
-import me.liuwj.ktorm.entity.add
-import me.liuwj.ktorm.entity.sequenceOf
 import org.kodein.di.Kodein
 import org.kodein.di.generic.instance
 import org.mindrot.jbcrypt.BCrypt
-import java.time.LocalDateTime
 
 class UserController(kodein: Kodein) : KodeinController(kodein) {
     private val simpleJwt by instance<SimpleJWT>()
-    private val db by instance<Database>()
+    private val userService by instance<UserService>()
 
     override fun Routing.registerRoutes() {
-
-
         post<Routes.Login> {
             data class Response(val token: String)
 
             val credential = call.receive<UsernamePasswordCredential>()
 
-            val (email, password) = db.from(Users)
-                .select(Users.email, Users.password)
-                .where { Users.username eq credential.username }
-                .map { row -> row[Users.email]!! to row[Users.password]!! }
-                .firstOrNull()
-                ?: return@post call.respond(HttpStatusCode.Unauthorized, ApiError.InvalidCredentialError)
+            val (email, password) = userService.getEmailAndPasswordFromUsername(credential.username)
+                ?: return@post call.respondStatus(HttpStatusCode.Unauthorized)
 
 
             if (!BCrypt.checkpw(credential.password, password)) {
-                return@post call.respond(HttpStatusCode.Unauthorized, ApiError.InvalidCredentialError)
+                return@post call.respondStatus(HttpStatusCode.Unauthorized)
             }
 
             return@post call.respond(Response(simpleJwt.sign(email)))
@@ -51,29 +39,18 @@ class UserController(kodein: Kodein) : KodeinController(kodein) {
         post<Routes.Register> {
             data class Response(val message: String)
 
-            val user = call.receive<RegisterInfo>()
+            val user = call.receive<UserRegistrationDto>()
 
-            val exists = db.from(Users)
-                .select()
-                .where { (Users.username eq user.username) or (Users.email eq user.email) }
-                .any()
-
-            if (exists) {
-                return@post call.respond(HttpStatusCode.Conflict, ApiError.ExistingUserError)
-            }
+            if (userService.userExists(user.username, user.email))
+                return@post call.respond(HttpStatusCode.Conflict)
 
             val hashedPassword = BCrypt.hashpw(user.password, BCrypt.gensalt())
 
-            val newUser = User {
-                this.username = user.username
-                this.email = user.email
-                this.password = hashedPassword
-                this.createdAt = LocalDateTime.now()
-            }
+            userService.createUser(
+                UserRegistrationDto(user.username, user.email, hashedPassword)
+            )
 
-            db.sequenceOf(Users).add(newUser)
-
-            return@post call.respond(HttpStatusCode.Created, Response("User created successfully"))
+            return@post call.respondStatus(HttpStatusCode.Created)
         }
     }
 
@@ -85,6 +62,4 @@ class UserController(kodein: Kodein) : KodeinController(kodein) {
         class Register
 
     }
-}
-
-data class RegisterInfo(val username: String, val email: String, val password: String)
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/api/src/errors/Errors.kt b/api/src/errors/Errors.kt
deleted file mode 100644
index c917a24..0000000
--- a/api/src/errors/Errors.kt
+++ /dev/null
@@ -1,7 +0,0 @@
-package be.vandewalleh.errors
-
-sealed class ApiError(val message: String){
-    object InvalidCredentialError : ApiError("Invalid credentials")
-    object ExistingUserError : ApiError("User already exists")
-    object DeletedUserError : ApiError("User has been deleted")
-}
diff --git a/api/src/services/UserService.kt b/api/src/services/UserService.kt
index 59dd579..67887d2 100644
--- a/api/src/services/UserService.kt
+++ b/api/src/services/UserService.kt
@@ -1,11 +1,15 @@
 package be.vandewalleh.services
 
+import be.vandewalleh.entities.User
 import be.vandewalleh.tables.Users
 import me.liuwj.ktorm.database.Database
 import me.liuwj.ktorm.dsl.*
+import me.liuwj.ktorm.entity.add
+import me.liuwj.ktorm.entity.sequenceOf
 import org.kodein.di.Kodein
 import org.kodein.di.KodeinAware
 import org.kodein.di.generic.instance
+import java.time.LocalDateTime
 
 /**
  * service to handle database queries for users.
@@ -25,4 +29,43 @@ class UserService(override val kodein: Kodein) : KodeinAware {
             .firstOrNull()
     }
 
-}
\ No newline at end of file
+    /**
+     * returns a user email and password from it's email if found or null
+     */
+    fun getEmailAndPasswordFromUsername(username: String): Pair<String, String>? {
+        return db.from(Users)
+            .select(Users.email, Users.password)
+            .where { Users.username eq username }
+            .limit(0, 1)
+            .map { row -> row[Users.email]!! to row[Users.password]!! }
+            .firstOrNull()
+    }
+
+    fun userExists(username: String, email: String): Boolean {
+        return db.from(Users)
+            .select(Users.id)
+            .where { (Users.username eq username) or (Users.email eq email) }
+            .limit(0, 1)
+            .firstOrNull() != null
+    }
+
+    /**
+     * create a new user
+     * password should already be hashed
+     */
+    fun createUser(user: UserRegistrationDto) {
+        db.useTransaction {
+            val newUser = User {
+                this.username = user.username
+                this.email = user.email
+                this.password = user.password
+                this.createdAt = LocalDateTime.now()
+            }
+
+            db.sequenceOf(Users).add(newUser)
+        }
+    }
+
+}
+
+data class UserRegistrationDto(val username: String, val email: String, val password: String)
\ No newline at end of file