work out basis of assesment. overlap profits mostly happen when you start trading. read the rules for basis of assesment.
first year of trade, you would always work out from start date of trading to the next april of the following year.
second year, must always be 12 months i believe. so in this second year, you would include some of the months from your first year to calculate taxable profit of that second year.
so therefore, you’re paying tax for those overlap months included in first year calculation and second year calculation. therefore, you’ll be paying tax twice on those overlap months.