There are numerous tax benefits to being married. But what if you get married to more than one person (which has been explicitly illegal in the UK since 1861)?

Weirdly, the tax system actually recognises polygamous marriages, where the individuals entered into the marriage in a country where polygamy is legal and those getting married were domiciled there. HMRC confirm this treatment in their manuals*.

That means that you could potentially transfer assets with no Capital Gains Tax to multiple spouses. Or when you die, fragment your assets to your many spouses with no Inheritance Tax at all – all of whom would be entitled to both their own Nil Rate Bands plus your transferred Nil Rate Band.**

In my career I’ve seen quite a few people marry for (partly) tax reasons. So why not multiple marriages for tax reasons?

* See CG22070 and IHTM11032

** This is almost certainly not what the legislation intends (indeed, I doubt the draftsman ever envisaged this situation). However, s8A IHTA 1984 does appear to allow you to transfer an unused Nil Rate Band to multiple spouses. This means that if you die and have three spouses, all three could inherit your Nil Rate Band of £325,000.