Section 12. A mutual bank shall have at least 25 corporators and may, at a legal meeting of the corporators, elect by ballot to be a corporator any person who is a resident of the commonwealth, or any person who resides in another state; provided, however, that not less than a majority of said corporators shall be citizens of the commonwealth and residents therein at any 1 time. Corporators shall be elected for a term of 10 years; provided, however, that a corporator shall not serve beyond the retirement age as established by the bank's by-laws. No person shall serve as a corporator of more than 1 savings bank and no corporator shall, after January 1, 1975, serve as an officer or director of a national bank, trust company, co-operative bank, savings and loan association or credit union. A corporator shall, at the time of the corporator's election or within 30 days thereafter, be a depositor of such corporation. Any person serving as a corporator of a savings bank may at the same time serve as a director or other officer of a trust company or a national bank that does not make real estate mortgage loans and does not accept savings deposits from natural persons.

No person shall continue to be a corporator after removing from the commonwealth unless, at the annual meeting following such removal, the corporators shall vote to continue such person as a corporator subject to the limitations of this section applicable to nonresident corporators.

Any person may, at an annual or special meeting of the corporators, cease to be a corporator if, at least 3 days before such meeting, the person has filed with the clerk a written notice of the corporator's intention so to do. If a corporator fails to attend 2 consecutive annual meetings, such corporator's membership may, by vote of the corporators at their next annual meeting, be declared forfeited and such action and vote when recorded shall be evidence of such forfeiture. Not more than 3/5 of the corporators of any such corporation shall be trustees or officers thereof at any 1 time.