Where I live, a salaried person will have tax automatically withheld and paid to authorities by their employer each week/fortnight. Someone self-employed usuall

Where I live, a salaried person will have tax automatically withheld and paid to authorities by their employer each week/fortnight. Someone self-employed usually has an estimate they pay quarterly or monthly, and then adjustments at the end of the financial year if the situation has varied from the estimate. I'm just saying I stockpile between tax bills (holding the cash against my mortgage to minimise interest) and my general style of living/spending means I can just redraw from the mortgage to make tax payments.