diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
index b9502bbe8..2529afad4 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoice.php
@@ -333,6 +333,23 @@ class PayUponInvoice {
 						)
 					);
 
+					$checkout_fields         = WC()->checkout()->get_checkout_fields();
+					$checkout_phone_required = $checkout_fields['billing']['billing_phone']['required'] ?? false;
+					if ( ! array_key_exists( 'billing_phone', $checkout_fields['billing'] ) || $checkout_phone_required === false ) {
+						woocommerce_form_field(
+							'billing_phone',
+							array(
+								// phpcs:ignore WordPress.WP.I18n.TextDomainMismatch
+								'label'        => __( 'Phone', 'woocommerce' ),
+								'type'         => 'tel',
+								'class'        => array( 'form-row-wide' ),
+								'validate'     => array( 'phone' ),
+								'autocomplete' => 'tel',
+								'required'     => true,
+							)
+						);
+					}
+
 					echo '</div><div>';
 
 					// phpcs:ignore WordPress.WP.I18n.TextDomainMismatch
@@ -376,6 +393,9 @@ class PayUponInvoice {
 				}
 
 				$national_number = filter_input( INPUT_POST, 'billing_phone', FILTER_SANITIZE_STRING );
+				if ( ! $national_number ) {
+					$errors->add( 'validation', __( 'Phone field cannot be empty.', 'woocommerce-paypal-payments' ) );
+				}
 				if ( $national_number ) {
 					$numeric_phone_number = preg_replace( '/[^0-9]/', '', $national_number );
 					if ( $numeric_phone_number && ! preg_match( '/^[0-9]{1,14}?$/', $numeric_phone_number ) ) {
diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoiceGateway.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoiceGateway.php
index 4596bd321..68d4a19a7 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoiceGateway.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PayUponInvoiceGateway.php
@@ -215,6 +215,12 @@ class PayUponInvoiceGateway extends WC_Payment_Gateway {
 			}
 		}
 
+		$phone_number = filter_input( INPUT_POST, 'billing_phone', FILTER_SANITIZE_STRING ) ?? '';
+		if ( $phone_number ) {
+			$wc_order->set_billing_phone( $phone_number );
+			$wc_order->save();
+		}
+
 		$wc_order->update_status( 'on-hold', __( 'Awaiting Pay upon Invoice payment.', 'woocommerce-paypal-payments' ) );
 		$purchase_unit  = $this->purchase_unit_factory->from_wc_order( $wc_order );
 		$payment_source = $this->payment_source_factory->from_wc_order( $wc_order, $birth_date );
diff --git a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
index 40bc9a15f..5e13ba0a8 100644
--- a/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
+++ b/modules/ppcp-wc-gateway/src/Gateway/PayUponInvoice/PaymentSourceFactory.php
@@ -24,8 +24,8 @@ class PaymentSourceFactory {
 	 * @return PaymentSource
 	 */
 	public function from_wc_order( WC_Order $order, string $birth_date ) {
-		$address = $order->get_address();
-
+		$address            = $order->get_address();
+		$phone              = filter_input( INPUT_POST, 'billing_phone', FILTER_SANITIZE_STRING ) ?? $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 ) {
@@ -44,7 +44,7 @@ class PaymentSourceFactory {
 			$address['last_name'] ?? '',
 			$address['email'] ?? '',
 			$birth_date,
-			preg_replace( '/[^0-9]/', '', $address['phone'] ) ?? '',
+			preg_replace( '/[^0-9]/', '', $phone ) ?? '',
 			$phone_country_code,
 			$address['address_1'] ?? '',
 			$address['city'] ?? '',