On 20 April 2016 we published AER Ring Fencing Guideline—Preliminary Positions Paper. The Preliminary Positions Paper sets out potential elements of the new ring-fencing guideline. The paper discusses possible approaches to ring-fencing issues that will need to be considered in preparing a ring-fencing guideline. We hope the preliminary positions suggested in the paper facilitate discussion. The paper discusses the objectives of ring-fencing, the services that will and will not be to be subject to ring-fencing, ring-fencing obligations, waivers and enforcement. It also includes case studies demonstrating how the new ring-fencing guideline may be applied.