Catherine Costley

Practice Areas

Catherine is a family lawyer working with clients through divorce and separation, advising on the financial arrangements upon entering or leaving a relationship, and all aspects of private children’s law. Pre- or post-nuptial agreements are commonplace in many of Catherine’s cases, reflecting the international nature of her client base. She advises regularly on financial provisions for unmarried parents under Schedule 1 of the Children Act and on child arrangement disputes, specific issues, and the permanent relocation of children.

Catherine’s clients are high-net-worth families whose financial affairs involve complexities such as offshore structuring, trusts, and complex corporate structures. She is very familiar with the financial affairs of those working in banking, private equity, finance, or law, but also entrepreneurs, sportsmen and women, actors/writers, and creatives.

Catherine regularly acts in high profile High Court cases and most recently acted in three reported financial remedies cases which brought new family law legal principles including an Appeal to the Court of Appeal.

Alongside the financial complexities, her clients’ relationships often feature difficult dynamics (for example, personality disorders, coercive control, abuse, and dependency, substance abuse and misuse), which Catherine is skilled at navigating. After lawyers step away, Catherine focuses on her clients’ lives: their financial security, co-parenting, or independence.

Catherine is listed in the Top 23 Divorce Lawyers on Midult.com’s directory, she is described as “serenity itself, methodical, thoughtful and kind” but also “progressive” and “fierce”. In Tatler magazine, she is described as “pin sharp”. Catherine is recommended in Spear’s Family Law Index 2024. In 2023, she appeared in Spear’s magazine’s feature on “Modern Family” as part of “a new generation of family lawyers whose stars are in the ascendant or at the apogee of their profession”.

Publications

https://www.fladgate.com/insights/we-all-learn-differently-neurodiversity-in-family-proceedings

https://www.fladgate.com/insights/changes-to-the-family-procedure-rules-to-encourage-non-court-dispute-resolution