Q: When taxing a lump sum amount with cents using the flat rates eg. $2500.80, do we include the 80 cents in the calculation?
The IRD PAYE tables states “in the dollar” but does not use examples with cents

A: From the IRD Payroll Calculations specification for lump sum payment it states to: Drop cents from the grossed up amount(truncate to whole dollars), e.g. $14,000.90 becomes $14,000.