Section 31B of the Income Tax (Trading and Other Income) Act 2005 sets the relevant maximum, which is the threshold for turnover above which an individual carrying on a trade, profession or vocation cannot use the cash basis to calculate their profits for income tax (but must calculate them in accordance with generally accepted accounting practice instead). Such an election may be made under section 25A if the conditions in section 31A are met. The relevant maximum is relevant for section 31A(2) (Condition A).