Sect. 248 e)...Nothing in this Code or in any other law shall stop the parties from requiring membership in a recognized collective bargaining agent as a condition for employment, except those employees who are already members of another union at the time of the signing of the collective bargaining agreement. Employees of an appropriate collective bargaining unit who are not members of the recognized collective bargaining agent may be assessed a reasonable fee equivalent to the dues and other fees paid by members of the recognized collective bargaining agent, if such non-union members accept the benefits under the collective agreement...
[Philippines, Labour Code]
Section 7. The employer shall not commit the acts set forth in the following items: to discharge or otherwise treat in a disadvantageous manner a worker by reason of such worker's being a member of a trade union, having tried to join or organize a trade union, or having performed proper acts of a trade union; or to make it a condition of employment that the worker must not join or must withdraw from a trade union. However, where a trade union represents a majority of workers employed at a particular plant or workplace, this shall not prevent an employer from concluding a collective agreement which requires, as a condition of employment, that the workers must be members of such trade union...
[Japan, Trade Union Law (Law No. 174 of 1 June 1949, as amended through Law No. 89 of 12 November 1993)]
Collective agreement may provide for union.
(1) Nothing in this Code is to be construed as precluding the parties to a collective agreement from inserting in it, or carrying out, a provision
(2) Despite subsection (1), a trade union or person acting on its behalf must not require an employer to terminate the employment of an employee due to his or her expulsion or suspension from that trade union on the ground that he or she is or was a member of another trade union.
[Canada (British Columbia), Labour Relations Code, Section 15]