(1) Where -

(a) money advanced or owing under a mortgage, or any part of it, is expressed to be advanced by or owing to two or more persons out of money, or as money, belonging to them on a joint account, or

(b) such a mortgage is made to two or more persons jointly and not in shares,

the mortgage debt, or other money or money's worth for the time being due to those persons, shall, as between them and the mortgagor, be deemed to belong to them on a joint account.

(2) The receipt in writing of -

(a) the survivors or last survivor of those persons, or

(b) the personal representative of the last survivor,

is a complete discharge for all money or money's worth for the time being due, notwithstanding any notice to the payer of a severance of such joint account.

(3) This section takes effect subject to the terms of the mortgage.