Where provision is made in a charging scheme for a charge to be paid in connection with the performance of a function by a charging authority, it is the duty of the charging authority to charge accordingly.

But the charging authority may waive a charge (in whole or in part) if it thinks fit to do so in a particular case.

This paragraph does not affect a charging authority's power to enter into an agreement for the payment to it of charges in respect of the performance of functions in respect of which a charging scheme does not provide for the making of a charge.