As Optus Customer Service seem to be clueless about this, I thought I would ask the question here. In order to complete an NBN installation, the ISP is asking for the ULL ID of my ADSL connection. How do I find out what this is?
If Optus was providing your ADSL broadband only Optus can provide you with the number. Have a look at this link:
If you can't get the number from Optus you will have to tell your new provider Optus will not provide the number and if they want your business they going to have to find the line themselves.