Section 81P. Any person wishing to cause to be recorded a plan of land situated in a city or town in which the subdivision control law is in effect, who believes that his plan does not require approval under the subdivision control law, may submit his plan to the planning board of such city or town in the manner prescribed in section eighty-one T, and, if the board finds that the plan does not require such approval, it shall forthwith, without a public hearing, endorse thereon or cause to be endorsed thereon by a person authorized by it the words ''approval under the subdivision control law not required'' or words of similar import with appropriate name or names signed thereto, and such endorsement shall be conclusive on all persons. Such endorsement shall not be withheld unless such plan shows a subdivision. If the board shall determine that in its opinion the plan requires approval, it shall within twenty-one days of such submittal, give written notice of its determination to the clerk of the city or town and the person submitting the plan, and such person may submit his plan for approval as provided by law and the rules and regulations of the board, or he may appeal from the determination of the board in the manner provided in section eighty-one BB. If the board fails to act upon a plan submitted under this section or fails to notify the clerk of the city or town and the person submitting the plan of its action within twenty-one days after its submission, it shall be deemed to have determined that approval under the subdivision control law is not required, and it shall forthwith make such endorsement on said plan, and on its failure to do so forthwith the city or town clerk shall issue a certificate to the same effect. The plan bearing such endorsement or the plan and such certificate, as the case may be, shall be delivered by the planning board, or in case of the certificate, by the city or town clerk, to the person submitting such plan. The planning board of a city or town which has authorized any person, other than a majority of the board, to endorse on a plan the approval of the board or to make any other certificate under the subdivision control law, shall transmit a written statement to the register of deeds and the recorder of the land court, signed by a majority of the board, giving the name of the person so authorized.

The endorsement under this section may include a statement of the reason approval is not required.