Thanks Ewout,
That works perfectly. Unfortunately the due date still populated as the order date however, learning from your reply I integrated a second snippet – which also works perfectly. You’ve been a great help.
add_filter( ‘woocommerce_xero_invoice_due_date’, ‘woocommerce_xero_invoice_due_date_month’, 10, 2 );
function woocommerce_xero_invoice_due_date_month($due_date){
return date_i18n(‘Y-m-d’, strtotime(“+30 days”));
}