diff --git a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp
index 5d35aa1..e3a85b0 100644
--- a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp
+++ b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp
@@ -472,7 +472,7 @@ Returns:
 */
 util::Map<std::string, const Invoice*> Controller::getAllInvoices()
 {
-    auto invoices = m_paymentManagementService.getAllInvoice();
+    auto invoices = m_paymentManagementService.getAllInvoices();
     util::Map<std::string, const Invoice*> readOnlyInvoice;
     for (int iterator = 0; iterator < invoices.getSize(); iterator++)
     {
@@ -489,7 +489,7 @@ Parameters:
 Returns:
     - void
 */
-void Controller::confirmPayment(std::string invoiceID)
+void Controller::confirmPayment(const std::string& invoiceID)
 {
     m_paymentManagementService.confirmPayment(invoiceID);
 }
diff --git a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h
index b045dec..35241a0 100644
--- a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h
+++ b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h
@@ -65,7 +65,7 @@ public:
     void removeComboPackage(const std::string& comboPackageID);
     util::Map<std::string, const Invoice*> getInvoicesByUser();
     util::Map<std::string, const Invoice*> getAllInvoices();
-    void confirmPayment(std::string invoiceID);
+    void confirmPayment(const std::string& invoiceID);
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
     util::Vector<const Notification*> getNotifications();
     void deleteNotification(const std::string& notificationID);
diff --git a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.cpp b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.cpp
index c28d31c..1fc1ff8 100644
--- a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.cpp
+++ b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.cpp
@@ -394,7 +394,7 @@ Parameters:
 Returns:
 	- util::Map<std::string, Invoice*>&: Map of invoice IDs to invoice objects
 */
-util::Map<std::string, Invoice*>& PaymentManagementService::getAllInvoice()
+util::Map<std::string, Invoice*>& PaymentManagementService::getAllInvoices()
 {
 	return m_dataStore.getInvoices();
 }
@@ -410,26 +410,22 @@ Returns:
 Throws:
 	- std::runtime_error if the invoice ID is invalid
 */
-void PaymentManagementService::confirmPayment(std::string invoiceID)
+void PaymentManagementService::confirmPayment(const std::string& invoiceID)
 {
-	std::string title, message;
 	auto& currentInvoices = m_dataStore.getInvoices();
 	int invoiceIndex = currentInvoices.find(invoiceID);
-	if (invoiceIndex != -1)
+	if (invoiceIndex == -1)
 	{
-		Invoice* invoice = currentInvoices.getValueAt(invoiceIndex);
-		if (invoice && invoice->getStatus() != util::PaymentStatus::COMPLETED)
-		{
-			User* currentUser = invoice->getBooking()->getCustomer();
-			invoice->setPaymentDate(util::Timestamp());
-			invoice->setStatus(util::PaymentStatus::COMPLETED);
-			title = "Payment Confirmed";
-			message = "Payment Confirmed for Invoice ID " + invoiceID;
-			sendNotification(currentUser, title, message);
-		}
+		throw std::runtime_error("Payment confirmation failed: invalid invoice ID.");
 	}
-	else
+	Invoice* invoice = currentInvoices.getValueAt(invoiceIndex);
+	if (!invoice || invoice->getStatus() != util::PaymentStatus::PAID)
 	{
-		throw std::runtime_error("Payment failed: invalid invoice ID.");
+		throw std::runtime_error("Payment confirmation failed: invoice is not awaiting confirmation.");
 	}
+	User* currentUser = invoice->getBooking()->getCustomer();
+	invoice->setStatus(util::PaymentStatus::COMPLETED);
+	std::string title = "Payment Confirmed";
+	std::string message = "Payment Confirmed for Invoice ID " + invoiceID;
+	sendNotification(currentUser, title, message);
 }
\ No newline at end of file
diff --git a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.h b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.h
index 79d525a..8961a2d 100644
--- a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.h
+++ b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/PaymentManagementService.h
@@ -28,8 +28,8 @@ public:
     void generateInvoice(ServiceBooking* booking);
     util::Map<std::string, Invoice*> getInvoices(const std::string& customerID);
     void completePayment(const std::string& invoiceID, util::PaymentMode paymentMode);
-    util::Map<std::string, Invoice*>& getAllInvoice();
-    void confirmPayment(std::string invoiceID);
+    util::Map<std::string, Invoice*>& getAllInvoices();
+    void confirmPayment(const std::string& invoiceID);
     void sendPaymentReminders();
     void sendNotification(User* user, const std::string& title, const std::string& message) override;
     void attach(User* user) override;
diff --git a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp
index 85a890a..76a1901 100644
--- a/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp
+++ b/Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp
@@ -503,7 +503,7 @@ void AdminMenu::displayUsers()
 /*
 Function: confirmPayment
 Description: Confirms payment for a selected invoice. Validates invoice status, updates payment date,
-			 sets status to PAID, and sends a notification to the customer.
+			 sets status to COMPLETED, and sends a notification to the customer.
 Parameters:
 	- invoiceID: std::string, ID of the invoice to confirm
 Returns:
@@ -520,19 +520,19 @@ void AdminMenu::confirmPayment()
 		util::pressEnter();
 		return;
 	}
-	bool hasPaidInvoice = false;
+	bool hasConfirmableInvoice = false;
 	for (int index = 0; index < invoiceList.getSize(); ++index)
 	{
 		const Invoice* invoice = invoiceList.getValueAt(index);
 		if (invoice && invoice->getStatus() == util::PaymentStatus::PAID)
 		{
-			hasPaidInvoice = true;
+			hasConfirmableInvoice = true;
 			break;
 		}
 	}
-	if (!hasPaidInvoice)
+	if (!hasConfirmableInvoice)
 	{
-		std::cout << "No pending invoices available for payment.\n";
+		std::cout << "No invoices awaiting confirmation.\n";
 		util::pressEnter();
 		return;
 	}