There are four grades of membership, related to the Society’s qualifications:
Simply being a member of the Society does not, in itself, reflect any knowledge or experience of indexing.
Any member taking the Society’s open learning course, Training in Indexing, is awarded the status of Student Member. Upon successful completion of the course, they are entitled to the status of Accredited Indexer (AI), while they remain members of the Society, and are awarded the grade of Professional Member.
Professional Members are indexers entitled to an entry in the Society's professional directory, Indexers Available, by virtue of having passed the Society's training course or suitable experience elsewhere.
Advance Professional Members are Professional members who have obtained an appropriate level of indexing experience over at least two years.
Advanced Professional Members with a further two years of experience may apply for Fellowship. They are required to sit a test paper (waived if within five years of Accreditation or passing the Advanced test paper), to submit an index for examination by the Society’s Assessors and to complete a searching questionnaire. If successful they receive the grade of Fellow for as long as they remain members of the Society.