21. Method of accounting

Unless otherwise provided by this Act, the timing of inclusions and deductions in calculating a person’s income shall be made according to generally accepted accounting principles.

An individual shall account for income tax purposes on a cash basis in calculating the individual’s income from an employment or investment.

An individual or entity conducting business shall account for income tax purposes on an accrual basis.

A person shall account for income tax purposes the income from sources other than the sources referred to in subsections (2) and (3) on either a cash or accrual basis, whichever properly computes the person’s income.

Subject to subsections (2) and (3), the

Where a person’s method of accounting changes, adjustments shall be made in the year of assessment following the change so that no item is omitted or taken into account more than once.