Apportionment may be stated to be this—that in the event of the termination of a life-interest by death, or of a more limited interest at a fixed period, the current rent or income shall be apportioned or paid over in such a way as to give the personal representatives of the party, or the party himself, as the case may be, a sum corresponding to the period that may have elapsed between the last date of payment and the death or other determination of the interest or estate. This was the effect of the Apportionment Act, 1834, which applies to the whole United Kingdom. It dealt chiefly with the cases of heirs of entail, liferenters, &c. The Apportionment Act of 1870 extends the principle to all rents, annuities, salaries, pensions, dividends, and other periodical payments, in the nature of income, so that all these now, like interest on money lent, are considered as accruing from day to day. When a person therefore dies, the income is counted up to the day of death, and is payable at the same time as the next quarterly or other payment would have been if no death had happened. The executor of the deceased, however, must recover the proportion, not from the tenant or debtor liable for the whole payment, but from the heir who receives it. Trade profits are not apportionable by virtue of the statute.
The word apportion is also used technically in English law to indicate (1) that a contract is divisible, so that a party may sue on one obligation, although he may not have performed all his obligations; (2) that a common of pasture may be divided proportionally among the owners of the common to which the pasture is attached.