TSEM9878 - Property held jointly by married couples or civil partners: Form 17 rule - general approach to declarations
Two factors should tend to reduce the scope for avoidance. First, the fact that a declaration is not retrospective - it applies only to income that arises from the date a valid declaration is signed. Second, the fact that the declaration must be sent to HMRC within 60 days of the date it is signed (TSEM9862). This means that a couple will usually need to make a decision about a declaration before they know their overall tax position for the year.
However, internal users should submit the case to Trusts Technical where it is considered that a couple have manipulated declarations; for example, a couple frequently declare large changes in beneficial interests with the effect of maximising the use of allowances, reliefs or losses in order to save tax.