I got in touch with one of TPG's support staff, and they told me that I was actually using the wrong ID for the request.   It turns out that the ID I thought I was meant to use was the old one, before TPG did a major infrastructure change and migrated to the new account website. The old ID was part of a linked account that was automatically added to the new account.   The updated information was reportedly relayed to me via email, although I will admit I probably missed it completely.   After contacting Telstra and using the new ID (Community ID from the new website) in the submission, the mobile number transfer went through after about 15 minutes.   PeteSA, you can try logging in with your mobile number or resetting your password. When I was getting support from TPG, they got me to log in to the new account portal, which showed my new ID, after resetting my password.   Thank you all for the replies. ... View more