You will need this registration if you intend to participate in the short term trading market (STTM).
A STTM is a wholesale gas market that supports short term trading between gas shippers, retailers and large customers at a defined hub. Once per day, the market uses participant bids and offers to schedule deliveries and withdrawals from gas pipelines at the hub for the next day. STTM hubs operate in Adelaide, Brisbane and Sydney.
Anyone who ships gas to, or withdraws gas from, a transfer point in the STTM hubs in Sydney, Adelaide, or Brisbane, is taken to participate in the STTM and must register as a shipper, user or both.