According to data published recently by the Office for National Statistics (ONS), the median duration of marriages ending in divorce was 13 years for opposite-sex couples in 2025 – the longest since the start of the time series in 1963.

The same study showed that the rate of married couples divorcing before reaching their tenth anniversary has also dropped and more couples are divorcing after longer marriages.

This is likely to increase the financial complexity of divorce proceedings, including the division of matrimonial assets and a greater likelihood that one or both parties will have an interest in a business.

Unsurprisingly, London has the most financially complex divorce settlements in England and Wales, with a score of 56.37 out of 100 according to the Financially Complex Divorce Index, significantly above the national average score of 34.37.

A financially complex divorce is one where the marital finances extend beyond standard liquid assets, such as the family home, savings and employment income, and require expert valuation, tracing or structuring.

These cases often involve high-net-worth (HNW) individuals, although not always, as a case can be financially complex even with a total wealth of less than £1 million – usually seen as the benchmark for cases involving HNW individuals – if the asset structures are difficult to disentangle or value.

Such cases usually involve the division of assets, such as shares in private companies or partnerships, cross-border bank accounts, property and/or investments located outside the UK.

As James Hardy, Forensic Director at Milsted Langdon, explains: “The latest study is interesting and the longer length of marriages will clearly increase the potential for complexity during a divorce.

“Individuals who fall into the financially complex category and are contemplating a divorce, particularly after a long marriage, may benefit from the expertise of a forensic accountant to help navigate the increasingly complex financial issues that can arise when substantial, diverse or business-related assets are involved.

“This trend is certainly intriguing and may run contrary to the wider public perception that many marriages are getting shorter. Divorcing later in life can often increase the complexity of financial settlements, as each spouse is likely to be more financially established and to have accumulated a broader range of assets and business interests.”