The legal term apportionment (French: apportionement; Mediaeval Latin: apportionamentum, derived from Latin: portio, share), also called delimitation,^[1] is in general the distribution or allotment of proper shares,^[2] though may have different meanings in different contexts. Apportionment can refer to estate, the amount of compensation received by a worker^[3] and in respect of time.

This term may be employed roughly and sometimes has no technical meaning; this indicates the distribution of a benefit (e.g. salvage or damages under the Fatal Accidents Act 1846, § 2), or liability (e.g. general average contributions, or tithe rent-charge), or the incidence of a duty (e.g. obligations as to the maintenance of highways).^[2]

Apportionment in respect of estate

Apportionment in respect of estate may result either from the act of the parties or from the operation of law.^[2]

Apportionment by act of the parties

Where a lessee is evicted from, or surrenders or forfeits possession of part of the property leased to him, he becomes liable at common law to pay only a rent apportioned to the value of the interest which he still retains. So where the person entitled to the reversion of an estate assigns part of it, the right to an apportioned part of the rent incident to the England,^[4] and in many of the British colonies.^[5] In the cases just mentioned there is apportionment in respect of estate by act of the parties.^[2]

Apportionment by operation of law

Apportionment by operation of law may be brought about where by act of law a lease becomes inoperative as regards its subject-matter, or by the "act of God", as, for instance, where part of an estate is submerged by the encroachments of the sea. To the same category belongs the apportionment of rent which takes place under various statutes (e.g. the Lands Clauses Consolidation Act 1845, § 119, when land is required for public purposes; the Agricultural Holdings Act 1883, § 41, in the case of a tenant from year to year receiving notice to quit part of a holding; and the Irish Land Act 1903 § 61, apportionment of quit and crown rents).^[2]

Apportionment in respect of time

At common law, there was no apportionment of rent in respect of time. Such apportionment was, however, in certain cases allowed in England by the Distress for Rent Act 1737, and the Apportionment Act 1834, and is now allowed generally. Under that statute (§2) all rents, annuities, dividends and other periodical payments in the nature of income are to be considered as accruing from day to day and to be apportionable in respect of time accordingly. It is provided, however, that the apportioned part of such rents, etc., shall only be payable or recoverable in the case of a continuing payment, when the entire portion of which it forms part itself becomes payable, and, in the case of a payment determined by re-entry, death or otherwise, only when the next entire portion would have been payable if it had not so determined (§ 3). Persons entitled to apportioned parts of rent have the same remedies for recovering them when payable as they would have had in respect of the entire rent; but a lessee is not to be liable for any apportioned part specifically. The rent is recoverable by the heir or other person who would, but for the apportionment, be entitled to the entire rent, and he holds it subject to distribution (§ 4). The Apportionment Act 1870 extends to payments not made under any instrument in writing (§2), but not to annual sums made payable in policies of insurance (§ 6). Apportionment under the act can be excluded by express stipulation.^[2]

The apportionment created by this statute is "apportionment in respect of time." The cases to which it applies are mainly cases of either:

1. apportionment of rent due under leases where at a time between the dates fixed for payment the lessor or lessee dies, or some other alteration in the position of parties occurs; or
2. apportionment of income between the representatives of a limited owner and the remainder-man when the limited interest determines at a time between the date when such income became due.^[2]

Apportionment of rent

With regard to the former of these classes, it may be noticed that although apportioned rent becomes payable only when the whole rent is due, the landlord, in the case of the bankruptcy of an ordinary tenant, may prove for a proportionate part of the rent up to the date of the receiving order;^[6] and that a similar rule holds good in the winding up of a company;^[7] and further that the act of 1870 applies to the liability to pay, as well as to the right to receive, rent.^[8] Accordingly, where an assignment of a lease is made between two half-yearly rent-days, the assignee is not liable to pay the full amount of the half-year's rent falling due on the rent-day next after the date of the assignment, but only an apportioned part of that half-year's rent, computed from the last mentioned date.^[2][9] If someone pays a ground rent on a leasehold property or a rentcharge on a freehold property that is also payable on other neighbouring properties, they can apply to the Department for Communities and Local Government for an 'order of apportionment' that legally separates their share of the ground rent or rentcharge.^[10]

Apportionment of income

With regard to the apportionment of income, the only points requiring notice here are that all dividends payable by public companies are apportionable, whether paid at fixed periods or not, unless the payment is, in effect, a payment of capital (§ 5).^[2]