TSEM9858 | Property held jointly by married couples or civil partners: Form 17 rule - no limit on number of declarations
From HM Revenue & Customs · Trusts, Settlements and Estates Manual
There is no limit on the number of declarations. Any number of declarations may be made to cover
new joint holdings
old joint holdings that have previously been dealt with on the standard 50/50 basis.
Couples may make numerous declarations in a year if they are constantly buying or selling investments in their joint names and holding them in unequal shares. In practice couples with a big turnover of assets may prefer to avoid joint holdings.
However, the declarations must reflect the actual position.