Philip Marcus is active in several international non-profit organizations as well as initiatives in several countries:

In-Between (Bein Le Vein in Hebrew) (Israel) is a non-profit organization founded with the goal of supporting children and families undergoing divorce and further on as they adjust to their new families.

Philip Marcus is a member of the professional advisory board and of the management committee. He also is the convener of the child-parent contact retention and alienation prevention working group, and of the working group to develop a handbook for divorcing and separating parents.

The Two Wishes Foundation. With non-profit company offices in the USA, Europe, Australia and the UK, and representatives in a dozen countries, our mission is to build healthier families around the world, protect children in separating families, and transform how we all think about, and deal with, family breakdown, separation and divorce.

Philip Marcus is co-founder of Two Wishes, and heads an international advisory group of family court judges.

Change for Children, based in England, is a group of stakeholders and professionals from around the world working for comprehensive reform, in the interests of children, of all the institutions and organizations who deal with families experiencing stress. Philip Marcus leads the Law and Legal group in Change for Children.

Co-Parenting Matters is a British collegiate group of interdisciplinary professionals with wide range of skills and experience spanning the separated family consultancy field.

Philip Marcus is President of Co-Parenting Matters.

AFCC – Association of Family and Conciliation Courts  is an interdisciplinary and international organization of professionals dedicated to the resolution of family conflict.

Philip Marcus has been a member for many years, has spoken at several international conferences, and has written for AFCC’s journal, Family Court Review.

PASG – Parental Alienation Study Group is an international, not-for-profit corporation whose members are interested in educating the general public, mental health clinicians, forensic practitioners, attorneys, and judges regarding parental alienation.

Philip Marcus has been a member for several years, and has co-headed the PASG Prevention Project, aimed at developing projects for prevention of parental alienation by publicity, and early identification and immediate intervention when there is a risk of alienation.

World Congress on Family Law and Children’s Rights brings together individuals and organizations from across the world who have influence on the legal and justice system, to protect the human rights of children and young people.

Philip Marcus has attended and lectured at several international conferences

International Centre for Family Law, Policy and Practice.

Philip Marcus has been consulted by and given lectures for the following entities:

Parental Alienation Europe (Ireland)

La Dolce Vita Project (Northern Ireland)

Happy Parenting (Malta)
PAS (Ukraine)