The legal term apportionment (; Mediaeval Latin: , derived from , share), also called delimitation, is in general the distribution or allotment of proper shares, 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).
In respect of estate
Apportionment in respect of estate may result either from the act of the parties or from the operation of law. and in many of the British colonies. In the cases just mentioned there is apportionment in respect of estate by act of the parties. and that a similar rule holds good in the winding up of a company; and further that the Apportionment Act 1870 applies to the liability to pay, as well as to the right to receive, rent. 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. 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.
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).