 The Single Rate Option (whereby FBT is paid at the highest FBT rate on all employees), or the "alternate rate option" (formerly the "multi-rate option", which involves attribution of benefits to individual employees and pooling of non-attributable benefits and certain de minimis benefits).There is a 'short form' way of calculating under the alternate rate option, which is simply to pool non-attributable and de minimis benefits but pay the highest rate of FBT on remaining benefits rather than attribute to employees.New Zealand FBT rates are determined by grossing up personal income tax rates.