Thomson Reuters names eight Keystone Law partners in its Stand-out Lawyers Guide 2026
Andrea James, Andrew Darwin & Anna McKibbin
Teresa is a family law specialist advising on all aspects of family law, including financial and child matters. Her work often includes issues of international as well as domestic law. She advises on pre-nuptial, post-nuptial, and cohabitation agreements as protective measures.
Teresa works with families whose wealth includes complex trust structures and corporate entities, and manages cases through the courts or by negotiation, as appropriate.
Teresa also acts in claims under the Inheritance (Provision for Family and Dependants) Act 1975 and in contested probate matters. She is a trained Mediator (family, civil and commercial), a Collaborative Lawyer, and a Tavistock-trained psychodynamic psychotherapist specialising in couples and relationship work.
She is a Fellow of the International Academy of Family Lawyers, a worldwide association of practising lawyers who are recognised by their peers as the most experienced and skilled family law specialists in their jurisdictions.
Teresa has an impressive team of external experts to assist including IFAs, investment advisers, tax and pension experts, and schooling and therapists/counsellors.
Teresa advises on complex family law matters involving high-value financial claims, cross-border assets, and intricate business or trust structures. Her expertise includes pre-nuptial agreements, Schedule 1 Children Act claims, and collaborative law solutions for international and high-net-worth clients.
Experience
Teresa advises on family mediation, helping clients resolve financial, inheritance, and child arrangement disputes. Her experience includes mediations involving complex pensions, international family dynamics, and Inheritance Act claims between spouses and adult children.
Experience
Teresa advises on complex children disputes involving allegations of harm, parental alienation, and international relocation. Her experience includes high-conflict cases requiring fact-finding hearings, safeguarding measures, and coordination with social services and child protection professionals.
Experience
Please note: The experience list above may include examples of work completed prior to joining Keystone Law.
Recognised by Chambers UK for Family/Matrimonial Finance: High Net Worth 2025–2026
Recognised by The Legal 500 for Family: Leading Partner 2025–2026
Recommended Lawyer in The Spear’s 500 Family Index 2025
Recipient of the ‘Women Who Will’ award from the Next 100 years organisation in recognition of exceptional work in developing and encouraging women in the Law
Fellow of The International Academy of Family Lawyers
Member of Resolution
Member of British Association for Counselling and Psychotherapy
“Teresa demonstrates the utmost professionalism in her field. Her experience, knowledge and ability to speak in plain language to clients is incredible.”
Chambers UK 2026
“Teresa wears her abilities lightly. She's strategic but in a very low-key way. She is very good at getting pragmatic, sensible outcomes.”
Chambers UK 2026
“Teresa Cullen is very experienced and very commercial.”
Chambers UK 2026
“Teresa Cullen is an excellent family lawyer. I have worked with her previously, and she is really thorough, supportive, and knowledgeable.”
The Legal 500 2026
“Teresa Cullen is absolutely first-rate. She mixes as an equal in the very top flight of London family lawyers.”
The Legal 500 2026
“Teresa Cullen is formidable in the knowledge she has about private and finance cases. She is not afraid to give the ‘tough advice’ which is often needed in these cases but does so in a sympathetic and knowledgeable way.”
The Legal 500 2025
“Teresa herself is a tough fighter for the interests of her clients. She has been in the game a long time and has a deserved reputation for thoroughness and tenacity.”
Chambers UK 2025
“Teresa Cullen shows exceptional skill in dealing with family issues, showing empathy and gently guiding the client to a sensible solution.”
The Legal 500 2024
Teresa qualified as a solicitor in 1985. Prior to joining Keystone Law in 2025, she worked at the following firms: