Add billing fields to user registration

// Add Billing Fields To Registration Form
add_action( 'woocommerce_register_form_start', function() {

	$countries = new WC_Countries();
	$billingfields = $countries->get_address_fields();
	unset( $billingfields['billing_email'] );
	$fields = apply_filters( 'woocommerce_billing_fields', $billingfields );

	foreach( $fields as $key => $field_args ) {
		woocommerce_form_field( $key, $field_args );
	}

}, 15 );

// Billing Fields Registration Validation
add_action( 'woocommerce_register_post', function( $username, $email, $validation_errors ) {

	if( empty( $_POST['billing_first_name'] ) ) {
		$validation_errors->add(
			'billing_first_name_error', __( 'Please provide a first name.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_last_name'] ) ) {
		$validation_errors->add(
			'billing_last_name_error', __( 'Please provide a last name.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_country'] ) ) {
		$validation_errors->add(
			'billing_country_error', __( 'Please select a country.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_address_1'] ) ) {
		$validation_errors->add(
			'billing_address_1_error', __( 'Please provide a street address.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_city'] ) ) {
		$validation_errors->add(
			'billing_city_error', __( 'Please provide a city or region.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_state'] ) ) {
		$validation_errors->add(
			'billing_state_error', __( 'Please select a state or province.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_postcode'] ) ) {
		$validation_errors->add(
			'billing_postcode_error', __( 'Please provide a postal code.', 'woocommerce' )
		);
	}

	if( empty( $_POST['billing_phone'] ) ) {
		$validation_errors->add(
			'billing_phone_error', __( 'Please provide a phone number.', 'woocommerce' )
		);
	}

	return $validation_errors;

}, 10, 3 );

// Save Billing Fields At Registration
add_action( 'woocommerce_created_customer', function( $customer_id ) {

	if( isset( $_POST['billing_first_name'] ) ) {
		update_user_meta(
			$customer_id, 'first_name', sanitize_text_field( $_POST['billing_first_name'] )
		);
		update_user_meta(
			$customer_id, 'billing_first_name', sanitize_text_field( $_POST['billing_first_name'] )
		);
	}

	if( isset( $_POST['billing_last_name'] ) ) {
		update_user_meta(
			$customer_id, 'last_name', sanitize_text_field( $_POST['billing_last_name'] )
		);
		update_user_meta(
			$customer_id, 'billing_last_name', sanitize_text_field( $_POST['billing_last_name'] )
		);
	}

	if( isset( $_POST['billing_company'] ) ) {
		update_user_meta(
			$customer_id, 'billing_company', sanitize_text_field( $_POST['billing_company'] )
		);
	}

	if( isset( $_POST['billing_country'] ) ) {
		update_user_meta(
			$customer_id, 'billing_country', sanitize_text_field( $_POST['billing_country'] )
		);
	}

	if( isset( $_POST['billing_address_1'] ) ) {
		update_user_meta(
			$customer_id, 'billing_address_1', sanitize_text_field( $_POST['billing_address_1'] )
		);
	}

	if( isset( $_POST['billing_address_2'] ) ) {
		update_user_meta(
			$customer_id, 'billing_address_2', sanitize_text_field( $_POST['billing_address_2'] )
		);
	}

	if( isset( $_POST['billing_city'] ) ) {
		update_user_meta(
			$customer_id, 'billing_city', sanitize_text_field( $_POST['billing_city'] )
		);
	}

	if( isset( $_POST['billing_state'] ) ) {
		update_user_meta(
			$customer_id, 'billing_state', sanitize_text_field( $_POST['billing_state'] )
		);
	}

	if( isset( $_POST['billing_postcode'] ) ) {
		update_user_meta(
			$customer_id, 'billing_postcode', sanitize_text_field( $_POST['billing_postcode'] )
		);
	}

	if( isset( $_POST['billing_phone'] ) ) {
		update_user_meta(
			$customer_id, 'billing_phone', sanitize_text_field( $_POST['billing_phone'] )
		);
	}

}, 10, 1 );