What if the prospective second wife is a foreign national?

You need polygyny permission from the Syariah Court and must meet additional requirements for marrying a foreign national. The religious affairs office usually asks for additional documents such as a passport, a letter from the prospective wife's embassy confirming she is single or divorced, and the wali's permission (or the wali hakim procedure if the wali is not in Malaysia). Some states also require support or a report from certain bodies. The spouse's immigration status (visit pass, spouse pass) is handled separately with the Immigration Department. Do not marry abroad to avoid the procedure, because it is still an offence. Consult your state religious affairs office, the state-by-state guide and cross-border marriage.