Facts: Amberley unilaterally increased the fees it charged for certain residents, but West Sussex refused to pay the increases. The issue was whether Amberley had been contractually entitled to increase the fees.

Judgment: the Court of Appeal (Mummery, Richards and Aikens LJJ) held that clear words in a contract would be required before a court concluded that one party was entitled to increase charges unilaterally. In this case, Amberley was not so entitled because the contract merely provided that the level of fees was subject to review if costs increased. That meant a joint review and any increases had to be agreed.