As part of Ofwat's decision on CPW070a/CPM043a – Phase 2 – Bilateral Transaction Programme, and as an interim solution and to mitigate the risk of customer detriment where bulk submission may occur in the Bilateral Hub, we required the development of the Bilateral Hub Submission Guidance. The Bilateral Hub Submission Guidance has been developed by the Market Operator, MOSL, in consultation with Trading Parties. The Bilateral Hub Submission Guidance (as amended) will be implemented on 22 September 2021. This guidance document has been approved as an interim measure with the enduring solution to be developed during the next phase of the programme. Trading Parties should note that they are obliged to comply with this guidance document.