Some people are using the extension of the civil partnership rules to heterosexual couples as an opportunity to highlight the ways in which the rules on inheritance tax ("IHT") favour married couples (or those in civil partnerships).

Whilst it seems unlikely at this stage that the Government will submit to calls to allow siblings similar access to these IHT exemptions, it does raise the interesting ethical question about why avoiding IHT continues to be so closely linked to marriage or civil partnerships. The argument that it is to preserve family wealth does not hold, because IHT is taxed at 40% when the surviving spouse does eventually pass wealth down to children. Indeed, a married couple receives the exemption whether or not they have children, whereas a different individual may wish to pass assets to a loved niece or nephew via their own sibling. In the former scenario IHT is only taxed once (on the death of the surviving spouse), whereas in the second scenario HMRC takes a 40% cut twice.

Given that the exemption simply requires that individuals be married or in a civil partnership, it begs the question of what the justification is for the continued generosity towards couples in the 21st century.