Section 26, The Post Office Savings Bank (Rate of Interest) Order

(a) An application to withdraw money deposited in thejoint names of two or more persons, or in the name of one person as trustee for another person, shall be signed by all such persons named in the account or by the survivor or survivors among such persons. (b) The Postmaster General shall require proof to his satisfaction of such survivorship. (c) The warrant issued on such applications shall be made out in the names of the applicants and their receipt shall be a good discharge to the Postmaster General for the sum stated in the warrant.