diff --git a/pom.xml b/pom.xml
index a2ee6a0..2239f21 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,6 +18,7 @@
         <quarkus.platform.version>3.12.0</quarkus.platform.version>
 
         <iban4j.version>3.2.8-RELEASE</iban4j.version>
+        <rest-assured.version>5.4.0</rest-assured.version>
         <quarkus-openapi-generator-server.version>2.4.2</quarkus-openapi-generator-server.version>
 
         <compiler-plugin.version>3.13.0</compiler-plugin.version>
@@ -91,6 +92,13 @@
             <version>3.26.0</version>
             <scope>test</scope>
         </dependency>
+
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <version>${rest-assured.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/main/java/ch/postfinance/swiss/hacks/service/LoginService.java b/src/main/java/ch/postfinance/swiss/hacks/service/LoginService.java
index 1b171bf..7981728 100644
--- a/src/main/java/ch/postfinance/swiss/hacks/service/LoginService.java
+++ b/src/main/java/ch/postfinance/swiss/hacks/service/LoginService.java
@@ -3,11 +3,13 @@
 import ch.postfinance.swiss.hacks.domain.Login;
 import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.transaction.Transactional;
+import jakarta.ws.rs.BadRequestException;
 
 import java.security.SecureRandom;
 import java.time.Instant;
 
 import static ch.postfinance.swiss.hacks.domain.Login.newLogin;
+import static org.apache.commons.lang3.StringUtils.isEmpty;
 
 @ApplicationScoped
 public class LoginService {
@@ -17,6 +19,9 @@ public class LoginService {
     @Transactional
     public RegistrationInformation register(String firstName, String lastName, Instant dateOfBirth) {
         // TODO: Some verification/validity checks, probably
+        if (isEmpty(firstName)){
+            throw new BadRequestException("First name is required");
+        }
 
         var password = String.valueOf(SECURE_RANDOM.nextInt(100_000, 100_000_000));
         var login = newLogin(firstName, lastName, dateOfBirth, password);
diff --git a/src/main/resources/openapi/openapi.yml b/src/main/resources/openapi/openapi.yml
index c93f7bc..5d3264d 100644
--- a/src/main/resources/openapi/openapi.yml
+++ b/src/main/resources/openapi/openapi.yml
@@ -10,7 +10,7 @@ paths:
   /customers/register:
     post:
       summary: Register a new customer
-      description: Allows a new customer to register for an online banking account.
+      description: Allows a new customer to register for an online banking account. U can later login using the returned credentials.
       requestBody:
         required: true
         content:
diff --git a/src/test/java/ch/postfinance/swiss/hacks/service/CustomerApiTest.java b/src/test/java/ch/postfinance/swiss/hacks/service/CustomerApiTest.java
new file mode 100644
index 0000000..48b5627
--- /dev/null
+++ b/src/test/java/ch/postfinance/swiss/hacks/service/CustomerApiTest.java
@@ -0,0 +1,77 @@
+package ch.postfinance.swiss.hacks.service;
+
+import io.quarkus.test.junit.QuarkusTest;
+import io.restassured.RestAssured;
+import io.restassured.http.ContentType;
+import io.restassured.path.json.JsonPath;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.notNullValue;
+
+@QuarkusTest
+public class CustomerApiTest {
+
+    @Test
+    public void testSuccessfulRegistration() {
+        // Define customer data
+        String firstName = "Foo";
+        String lastName = "Bar";
+        String dateOfBirth = "2000-01-01";
+
+        // Build request body
+        String requestBody = String.format("{" +
+                "\"firstName\": \"%s\"," +
+                "\"lastName\": \"%s\"," +
+                "\"dateOfBirth\": \"%s\"" +
+                "}", firstName, lastName, dateOfBirth);
+
+        // Send POST request and verify response
+        String response = RestAssured.given()
+                .contentType(ContentType.JSON)
+                .body(requestBody)
+                .post("/customers/register")
+                .then()
+                .statusCode(200) // TODO: this should be 201 according to spec!
+                .body("username", equalTo((firstName + "." + lastName).toLowerCase()))
+                // Replace "expected_password" with the actual password generation logic
+                .body("password", notNullValue())
+                .extract().asString();
+
+        // Extract username from response
+        String username = JsonPath.from(response).getString("username");
+        String password = JsonPath.from(response).getString("password");
+
+        // Send login request with extracted username and password
+        RestAssured.given()
+                // .contentType(ContentType.FORM)  // Use form data for login
+                .formParam("j_username", username)
+                .formParam("j_password", password)
+                .post("/j_security_check")
+                .then()
+                .statusCode(302)
+                .header("location", contains("/index.html"));
+    }
+
+    @Test
+    public void testMissingRequiredField() {
+        // Define customer data with missing first name
+        String lastName = "Doe";
+        String dateOfBirth = "2000-01-01";
+
+        // Build request body
+        String requestBody = String.format("{" +
+                "\"lastName\": \"%s\"," +
+                "\"dateOfBirth\": \"%s\"" +
+                "}", lastName, dateOfBirth);
+
+        // Send POST request and verify response
+        RestAssured.given()
+                .contentType(ContentType.JSON)
+                .body(requestBody)
+                .post("/customers/register")
+                .then()
+                .statusCode(400);
+    }
+}