Sec. 1(4) of the Act provides that where it appears to the Central Provident Fund Commissioner, whether on an application made to him in this behalf or otherwise, that the employer and the majority of employees in relation to any establishment have agreed that the provisions of this Act should be made applicable to the establishment, he may, by notification in the Official Gazette, apply the provisions of this Act to that establishment on and from the date of such agreement or from any subsequent date specified in such agreement. Thus Section 1(4) provides for voluntary option to make applicable to the Act. Sec. 1(5) of the Act provides that an establishment to which this Act applies shall continue to be governed by this Act notwithstanding that the number of persons employed therein at any time falls below twenty.