diff --git a/modules/ppcp-vaulting/src/CustomerApprovalListener.php b/modules/ppcp-vaulting/src/CustomerApprovalListener.php
index 009fb451c..19ea6ace7 100644
--- a/modules/ppcp-vaulting/src/CustomerApprovalListener.php
+++ b/modules/ppcp-vaulting/src/CustomerApprovalListener.php
@@ -55,7 +55,7 @@ class CustomerApprovalListener {
 	public function listen(): void {
 		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
 		$token = wc_clean( wp_unslash( $_GET['approval_token_id'] ?? '' ) );
-		if ( ! $token ) {
+		if ( ! $token || is_array($token) ) {
 			return;
 		}
 
diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
index 63c4eee9b..fe152e0bd 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
@@ -421,12 +421,12 @@ class PayUponInvoice {
 
 				// phpcs:ignore WordPress.Security.NonceVerification.Missing
 				$birth_date = wc_clean( wp_unslash( $_POST['billing_birth_date'] ?? '' ) );
-				if ( ( $birth_date && ! $this->checkout_helper->validate_birth_date( $birth_date ) ) || $birth_date === '' ) {
+				if ( ( $birth_date && is_string( $birth_date ) && ! $this->checkout_helper->validate_birth_date( $birth_date ) ) || $birth_date === '' ) {
 					$errors->add( 'validation', __( 'Invalid birth date.', 'woocommerce-paypal-payments' ) );
 				}
 
 				// phpcs:ignore WordPress.Security.NonceVerification.Missing
-				$national_number = wc_clean( wp_unslash( $_POST['billing_phone'] ?? 0 ) );
+				$national_number = wc_clean( wp_unslash( $_POST['billing_phone'] ?? '' ) );
 				if ( ! $national_number ) {
 					$errors->add( 'validation', __( 'Phone field cannot be empty.', 'woocommerce-paypal-payments' ) );
 				}
@@ -532,7 +532,7 @@ class PayUponInvoice {
 			function( string $post_type ) {
 				if ( $post_type === 'shop_order' ) {
 					// phpcs:ignore WordPress.Security.NonceVerification.Recommended
-					$post_id = wc_clean( wp_unslash( $_GET['post'] ?? 0 ) );
+					$post_id = wc_clean( wp_unslash( $_GET['post'] ?? '' ) );
 					$order   = wc_get_order( $post_id );
 					if ( is_a( $order, WC_Order::class ) && $order->get_payment_method() === PayUponInvoiceGateway::ID ) {
 						$instructions = $order->get_meta( 'ppcp_ratepay_payment_instructions_payment_reference' );
diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
index 960a82f87..0388132c5 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
@@ -26,7 +26,10 @@ class PaymentSourceFactory {
 	public function from_wc_order( WC_Order $order, string $birth_date ) {
 		$address = $order->get_address();
 		// phpcs:ignore WordPress.Security.NonceVerification.Missing
-		$phone              = wc_clean( wp_unslash( $_POST['billing_phone'] ?? '' ) ) ?? $address['phone'] ?? '';
+		$phone = wc_clean( wp_unslash( $_POST['billing_phone'] ?? '' ) );
+		if ( ! $phone ) {
+			$phone = $address['phone'] ?? '';
+		}
 		$phone_country_code = WC()->countries->get_country_calling_code( $address['country'] );
 		$phone_country_code = is_array( $phone_country_code ) && ! empty( $phone_country_code ) ? $phone_country_code[0] : $phone_country_code;
 		if ( is_string( $phone_country_code ) && '' !== $phone_country_code ) {