Where a charge is registered in the names of two or more proprietors (whether jointly or in undivided shares) the mortgage term implied or comprised in the charge shall (but without prejudice to the beneficial interests in the mortgage money) vest in them as joint tenants, and the proprietors or the survivors or survivor of them or the personal representatives of the last survivor, shall have power to give valid receipts, notwithstanding that the mortgage money may be held in undivided shares, in like manner as if the money had been held on a joint account.