Good boards should always have agreed terms of office so that there is a regular turnover of trustees and boards remain vibrant. Two terms of three years with a review at the end of the first term is fairly typical.
Some charities also have provision for a third term, so that someone who is appointed as an officer - a chair, vice chair or treasurer - in the middle of their term as trustee can serve a potential six years in that position. But no matter when officers are appointed, their term as trustees would not normally be more than nine years.
Retirement from the board need not necessarily mean goodbye. New roles are developing that enable experience and skills gained by highly valued trustees to be retained by the charity.
Retiring trustees may be appointed as vice-presidents or ambassadors of the charity. They might also be invited to play a role on project groups or sub-committees. Charities should feel free to think creatively to identify more such ways to retain outstanding skills without breaching best governance practice.