diff --git a/plugins/woocommerce/changelog/fix-50245-fatal-error-checkout-customer b/plugins/woocommerce/changelog/fix-50245-fatal-error-checkout-customer
new file mode 100644
index 00000000000..28a5c165430
--- /dev/null
+++ b/plugins/woocommerce/changelog/fix-50245-fatal-error-checkout-customer
@@ -0,0 +1,4 @@
+Significance: minor
+Type: fix
+
+Address a fatal error that could happen if certain properties of the main WooCommerce class were accessed before WooCommerce had finished initializing
diff --git a/plugins/woocommerce/includes/class-woocommerce.php b/plugins/woocommerce/includes/class-woocommerce.php
index a8949206d52..09e97597af8 100644
--- a/plugins/woocommerce/includes/class-woocommerce.php
+++ b/plugins/woocommerce/includes/class-woocommerce.php
@@ -113,14 +113,14 @@ final class WooCommerce {
 	 *
 	 * @var WC_Cart
 	 */
-	public $cart = null;
+	private $cart = null;
 
 	/**
 	 * Customer instance.
 	 *
 	 * @var WC_Customer
 	 */
-	public $customer = null;
+	private $customer = null;
 
 	/**
 	 * Order factory instance.
@@ -199,7 +199,7 @@ final class WooCommerce {
 			return $this->api;
 		}
 
-		if ( in_array( $key, array( 'payment_gateways', 'shipping', 'mailer', 'checkout' ), true ) ) {
+		if ( in_array( $key, array( 'payment_gateways', 'shipping', 'mailer', 'checkout', 'customer', 'cart' ), true ) ) {
 			return $this->$key();
 		}
 	}
@@ -213,6 +213,8 @@ final class WooCommerce {
 	public function __set( string $key, $value ) {
 		if ( 'api' === $key ) {
 			$this->api = $value;
+		} elseif ( in_array( $key, array( 'customer', 'cart' ), true ) ) {
+			$this->$key = $value;
 		} elseif ( property_exists( $this, $key ) ) {
 			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
 			trigger_error( 'Cannot access private property WooCommerce::$' . esc_html( $key ), E_USER_ERROR );
@@ -1154,6 +1156,28 @@ final class WooCommerce {
 		return WC_Shipping::instance();
 	}
 
+	/**
+	 * Get customer class.
+	 *
+	 * @return WC_Customer
+	 */
+	public function customer() {
+		$this->initialize_cart();
+
+		return $this->customer;
+	}
+
+	/**
+	 * Get cart class.
+	 *
+	 * @return WC_Cart
+	 */
+	public function cart() {
+		$this->initialize_cart();
+
+		return $this->cart;
+	}
+
 	/**
 	 * Email Class.
 	 *