The parties to an access agreement may at any time vary or revoke the agreement.
A variation or revocation of an access agreement must be in writing.
An access agreement that is varied under this section continues to have effect as an access agreement for the purposes of this Chapter.
The effect of an access agreement being revoked is that it ceases to be an access agreement for the purposes of this Chapter.
A variation or revocation of an access agreement takes effect—
only if the parties jointly notify the Central Arbitration Committee of the variation or revocation in the prescribed form and manner;
only in respect of times after the day on which the Central Arbitration Committee is so notified.