WooCommerce Customer / Order CSV Export | Add a column to show custom text based on if there was sales tax or not

woocommerce-customer-order-csv-export-tax-status.php

<?php

/**
 * Order Export
 * Within the Custom Formats > Column Mapping, add your custom column name and set the Data Source to Static, and leave the Value field blank (since we set it here instead anyway)
 * This function sees if your order or line item had any tax, and if so, it fills your custom column with "Taxed". Otherwise, the column will say "Not Taxed".
 */
function fs_wc_csv_export_trim_data( $order_data ) {
	for( $i = 0; $i < count( $order_data ); $i++ ) {
		if ( isset( $order_data[ $i ]['order_line/tax_id/id'] ) ) {
			$taxage = $order_data[ $i ]['tax_total'];
			//If there is tax, then change the amount to custom text instead
			if( $taxage > 0 ) {
				$order_data[ $i ]['order_line/tax_id/id'] = 'Taxed';
			}
			else {
				$order_data[ $i ]['order_line/tax_id/id'] = 'Not Taxed';
			}
		}
	}
	return $order_data;
}
add_filter( 'wc_customer_order_csv_export_order_row', 'fs_wc_csv_export_trim_data' );