The owner of any hereditament the rent of which ; becomes payable or is collected at intervals shorter than quarterly may by agreement in writing with the rating authority undertake either—
(a) that he will pay the rates chargeable in respect of the hereditament whether it is occupied or not; or
(b) that he will so long as the hereditament is occupied pay the rates chargeable in respect of it; or
(c) that he will on behalf of the authority collect the rates due from the occupier of the hereditament;
and the authority may agree, where the owner so undertakes and pays over to the authority on or before the date or dates specified in the agreement the amounts payable by him thereunder, to make him an allowance not exceeding in the case of an undertaking under paragraph (a) of this subsection ten per cent., in the case of an undertaking under paragraph (b) thereof seven and a half per cent., or in the case of an undertaking under paragraph (c) thereof five per cent.
An allowance made under subsection (1) of this section in respect of any hereditament to an owner who is rated under section 55 of this Act shall be in substitution for any allowance to which he might otherwise have been entitled in respect of that hereditament under the said section 55.
An agreement entered into under this section shall con tinue in force until determined by notice given either by the rating authority to the owner or by the owner to the rating authority, and in the event of a change in the ownership of any hereditament while the agreement is in force shall continue to be binding upon the new owner as if it had been made by him.
A notice for the purposes of subsection (3) of this section shall take effect only on the expiration of a rate period and shall be given before the commencement of that period.
In the case of an undertaking by an owner under sub section (1)(c) of this section, the amount due from the owner shall be taken to be an amount which bears to the total amount of the rates due the same proportion as the aggregate amount actually collected by him in respect of rent and rates bears to the aggregate amount due in respect thereof.
In the case of an undertaking by an owner under subsection (1)(c) of this section, unless the undertaking expressly so provides—
(a) the expression " rates due " in the provisions of this section relating to such an undertaking shall not include rates accruing due before the date on which the undertaking comes into operation; and
(b) account shall not be taken for the purposes of subsection (5) of this section of rent which accrues due before that date.
Section 177 of the City of London Sewers Act 1848 shall not apply to any hereditament in the City of London so long as an undertaking in respect of that hereditament is in force under subsection (1)(a) of this section.