The Mar Thoma Church has entered into communion relationship with the Anglican Communion. So the Mar Thoma Church is a permanent invitee to the Lambeth Conference of the Anglican Communion. Agreements were signed separately with respective churches in different parts of Oikumene, like UK, USA, Canada, Australia and Arabian Gulf and so on. It is of historical importance that the Mar Thoma Metropolitan and the Primate of the Anglican church of Canada signed an agreement at venue of the WCC Vancouver Assembly. Nilakal Committee brought together all the churches in Kerala to have a common front and focused action with a ‘Common Altar’.

The Christian Conference of Asia was constituted as the East Asia Christian conference by the decision of churches, national council of churches and national Christian Councils who met at Prapat, Indonesia in March 1957. The first Assembly was held in 1959 at Kuala Lumpur. The Mar Thoma Church was represented in its leadership by the Rt. Rev. Dr. Joseph Mar Thoma. He is one of the four members of the Presidium of CCA.

The Mar Thoma Church played a significant role in the formation and growth of the National Council of churches which is the National Ecumenical Forum in India. Formerly it was known as National Missionary council (1914). The Diocese of North America and Europe is part of the National council of churches in the United States of America.

The Mar Thoma Church in her ecumenical journey has covered a lot of miles. CSI – CNI – MTC Joint Council (1978), one its great achievements. We were not satisfied with such an arrangement and wanted to push the relationship further. It went further and now we have the Communion of Churches in India (2004).

Mar Thoma Church has been actively involved with the KCC from its inception. The Kerala Council of Churches the regional expression of the NCCI. Bishops have taken leadership as its Presidents and the clergy as its General Secretaries.