Then make sure your retainer is a contentious business agreement or your bills of costs are final statute bills, says Simon Browne KC. Over 25 years ago, Lord Justice Simon Brown (as he then was) in the case of Abedi v Penningtons [2000] 2 Costs LR 205 said a solicitor/client retainer was a complete retainer where monies were not due until completion. Nevertheless, he observed that it was open to solicitors to agree the terms of payment under their retainer and the wiser amongst them did so.