An administration charge is payable only to the extent that the amount of the charge is reasonable.
An administration charge is payable to an estate manager only if—
its amount appeared for the required period on an administration charge schedule published under section 84, or
its amount was determined in accordance with a method that appeared on the published administration charge schedule for the required period.
"The required period" is the period of 28 days ending with the day on which the administration charge is demanded to be paid.
An administration charge is not payable to an estate manager if—
the charge relates to the same matter as, or a matter of a similar nature to, a matter for which an administration charge is payable by another person to the estate manager,
the amount of the charge is different from the charge payable by that other person, and
it is not reasonable for the amount of the charge to be different.