Whilst changes to the “non-dom” rules in April 2025, and other tax changes, have resulted in a significant exodus of high and ultra-high net worth individuals from the UK over the past year, it seems that the English courts are very much open for business for international high and ultra-high net worth individuals, and in particular when it comes to divorce.
The UK’s reputation as a top destination for international divorces is not a new one, but the recent and ongoing high-profile battle of the Russian oligarch Vladimir Potanin, said to be one of the richest men in Russia, and his ex-wife Natalia Potanina, has made new law not only for the sums involved (which will be the highest of any “top up” financial claim in the English courts) but also in modifying the test and links to the UK that have historically been needed to obtain permission to bring “top up” financial claims in England after an overseas divorce. The previously required “strong connection” with England by a couple jointly during the marriage has been disregarded in this case, widening the net to future applicants for such top ups, as well as removing the need for what had previously been called a “knock out” blow to obtain permission to bring “top up” financial proceedings in England and Wales.
Now over 40 years old, Part III of the Matrimonial and Family Proceedings Act 1984 allows English and Welsh judges to order additional financial provision for parties who have divorced abroad. Known colloquially as Part III or “top up” applications, these have been a useful tool to fill the gap where other jurisdictions cannot or will not make sufficient financial provision for the financially weaker party. The wide discretion of judges and the starting point that division of capital should be on a 50:50 basis, irrespective of the parties’ financial contributions to a marriage, has also added to the UK’s attraction as a “divorce capital”.
In Natalia Potanina’s case, she and Vladimir Potanin, both in their 60s, were Russian citizens and have 3 adult children. Throughout the marriage, the couple lived in Russia, and it was only post-separation that Mrs Potanina obtained an investor visa for the UK and purchased a property in London in 2014. The parties were not always wealthy but became “massively rich” (according to Sir Jonathan Cohen who dealt with Mrs Potanina’s original permission application).
The marriage broke down in 2014 and was dissolved by a Russian court in February 2014. There followed a “blizzard of litigation” in Russia over the division of the parties’ finances. The wife also launched proceedings, for disclosure in Cyprus and the USA. By its final financial remedy order, the Russian court divided all of the “marital property” equally between the parties. However, the Russian court was only able to consider and make orders against assets where the parties hold the legal title to those assets, but not assets held in trust or through corporate structures, where the majority of the husband’s assets/wealth was held (around $20bn). According to the wife, she was only awarded 1% of their marital assets by the Russian court and was denied an award of US$6 billion.
She therefore issued her Part III application in the English courts in October 2018, after moving to her new property in London in 2017. Courts in England and Wales can consider any assets or beneficial interests of the parties, regardless of their structure and wherever they are located in the world and are generally known to be more favourable to the financially weaker party in divorce matters. Further rounds of litigation in London have ensued, leading to a visit to the Supreme Court and two visits to the Court of Appeal. The latest Court of Appeal decision was handed down in September 2025 allowing Mrs Potanina’s permission application, meaning that she can now move to stage two of the process where the court looks at quantifying Mr Potanin’s wealth and how and if it should be divided as part of the “top up” exercise.
Whilst it has not been a straightforward process for Mrs Potanina to get to this stage, and she still faces a struggle to show whether a further order for financial provision is required, it is thought that she has helped pave the way for future applicants for Part III “top ups” who have only recently arrived in the UK post-separation and do not have a “knock out” blow for permission being granted, but instead can show a “substantial ground” for making the application in England and Wales.
If you have any questions arising from this article or would like to discuss matters in more detail, please contact Winckworth Sherwood LLP’s Family team who are experienced in cross-jurisdictional high net worth family matters involving complex asset ownership structures.