In 1967 Ken Miller was appointed to fill a casual vacancy on the NSW Credit Union League Co-operative Ltd. In the same year he was chosen with Dermot Ryan as a delegate to the CUNA conference. On his return he was elected Chairman of the League. While at the CUNA conference he learnt the necessity for a savings protection fund; a collections department and a supply department and most of these were achieved within five years.
He was a Director of the Association of NSW Credit Unions from 1967 – 1984. He retired as General Manager of the NSW Teachers’ Credit Union in June 1987.
On 26 January 1988 he became a Member of the Order of Australia "For service to the Credit Union movement".
Ken Miller provided an oral history interview for the credit union movement in 1987 when he was interviewed by Sara Pantzer.