There is a lot of case law to indicatge that the subscriber to the Memorandum is liable to pay for & take the shares which he indicates against his name, under the subscripttion clause of the MoA.
However, there is no indication as to the waiting period. In a case where one of the subscibers has not paid for the number shares which he agreed to take (under the subscripttion clause) - can the Board treat those shares as free & issue such shares to another person.