All ISC20C membership records are received and maintained by the Secretary General (SG). The SG retains the membership archive of all membership applications, CVs and membership decisions. A membership sub committee may be appointed, or the Bureau may function as such. Secretary General provides membership summary at the AGM of the ISC 20C and for the ICOMOS annual report.

Membership categories are designated by ISC20C Statutes (2020), which are made available on the website.

The ISC20C statutes are very specific about requiring members to be active and encouraging emerging professionals to become involved. It is hoped that existing members will introduce at least one younger member each year.

A requirement of ISC20C membership is that members are active. The Bureau will have the right to dismiss any member who is inactive for more than one year without explanation, who commits an action which may bring the Committee into disrepute, or who does not behave in accordance with the Ethical Commitment Statement for ICOMOS Members. Dismissal procedures will include notification of the ICOMOS International Secretariat

The ISC20C Action Plan will include training initiatives in relation to Twentieth Century Heritage and opportunities for associate members and young professionals to develop their specialist knowledge and competency in Twentieth Century Heritage conservation.