How to get the SRN for Australian stock holdings?

We hold all Australian assets under a custodial structure which are registered under IBKR's name at one omnibus account with our custodian, BNP Australia. Hence, stock is held on CHESS under the one HIN but underlying clients do not have a unique HIN for themselves…

The bank accounts at each bank use an Omnibus account structure and are opened under Interactive Brokers’ name. The account title makes it clear that the funds in the account are held for the benefit of IBKR’s customers. The bank does not know the names of individual customers. IBKR and the program administrator have records showing how much each client has at each bank and, in the event of a bank default, would provide the records to FDIC. …

SRN stands for Securityholder Reference Number. An SRN is used to identify the owner of the shares that are held by a share registry (i.e. Issuer Sponsored Shares).

Shareholders can find out how their shares are held from the reference number on the top right corner of their latest holding or dividend statement. If the reference number begins with an "I" or "C"  and is followed by nine to eleven numbers, this is a Shareholder Reference Number (SRN) which means the shares are Issuer Sponsored. There are unique SRN numbers for each Issuer Sponsored holding…

IBKR does not provide the Investor Code (IVC) or Shareholder Reference Number (SRN) for UK equities to customer…