This is where the non trade income and expenses can be automatically adjusted in the company's adjusted trading/business profit.
No Primary Trade Box Ticked
You can allocate the income/expenses to a specific trade/business.
If you do not want to allocate the income/expenses to a specific trade/business then allocate then to non trade.
Primary Box Ticked
If the primary trade box is ticked then the income/expenses will be automatically allocated to the primary trade.
If there is more than one trade/business than the trade allocation grid will appear. You can then allocate the income/expenses as appropriate.