A mortgagee may spend such money as is necessary—
(a) for the preservation of the mortgaged property from destruction, forfeiture or sale;
(b) for supporting the mortgagor's title to the property;
(c) for making his own title thereto good against the mortgagor; and
(d) when the mortgaged property is a renewable lease-hold, for the renewal of the lease;
and may, in the absence of a contract to the contrary, add such money to the principal money, at the rate of interest payable on the principal, and, where no such rate is fixed, at the rate of nine per cent. per annum:
Provided that the expenditure of money by the mortgagee under clause (b) or clause (c) shall not be deemed to be necessary unless the mortgagor has been called upon and has failed to take proper steps to support his title or to make the mortgagee's title good, as the case may be.
Legal Commentary & Landmark Judgments: Section 72
Section 72 empowers a mortgagee in possession to spend money for the preservation of mortgaged property, defense of title, and renewal of leases, and to add such expenses to the principal mortgage debt with interest.
Preserve all municipal tax receipts, litigation expense vouchers, and repair bills incurred while in possession; these are fully recoverable from the mortgagor under Section 72 upon redemption.