The extent of the share (England, Wales and Northern Ireland): When are the beneficial interests ascertained?
In the case of Pettitt v Pettitt  AC 777 it is considered that
- the beneficial interests (IHTM15011) in assets that are acquired jointly must be ascertained as a matter of common intention immediately after those assets have initially been acquired (whether by spouses or civil partners (IHTM11032) or by other persons), and
- After that those interests remain the same unless and until they are modified by some subsequent agreement either express or to be implied from the circumstances.
You should refer any case where the taxpayer or agent argues that the intention of the parties should be established by examining the whole course of dealings between the parties relevant to the property in question.