QuickBooks uses tax tables to determine the rates and limits for federal,
state, and specific local taxes. The tax table automatically handles rounding
discrepancies and retroactive tax rate changes for flat-rate taxes, including
social security, FUTA, SUI, and some SDI taxes.
If you still feel that the taxes have been under or overwithheld,
you'll need to contact the payroll service to create a liability adjustment for a tax that's handled by