Extract from Property Income Manual PIM1030
Husbands and wives or civil partners living together should generally be treated as entitled in equal shares to income from jointly held property.
See ICTA88/S282A for years up to 2006-07, and ITA07/S836 for 2007-08 onwards.
However, this rule will not apply in any of the following instances:
>> the income is earned income (or, like furnished holiday lettings, treated as earned income) - ICTA88/S282A (4)(a), ITA07/S836 Exception D,
>> there is actually a partnership - ICTA88/S282A (4)(b), ITA07/S836 Exception C,
in this case the income is divided according to the terms of the partnership agreement,
>> both husband and wife, or both civil partners, have signed a declaration under ICTA88/S282B or ITA07/S837 stating their beneficial interests in both the property and the income arising from it,
but a declaration is only valid if their interests in the income and in the property itself correspond.