It would be great to have a tiny bit more explanation...what contract? Broadband or Mail Plus? Have you just switched to TalkTalk, renewed a contract or something else?
Check your Community Profile Personal Information (Click here) includes your name, current (TalkTalk?) landline 'phone number and an alternate number (mobile recommended) and address with postcode (location). Add, then scroll down and add your email address to Private notes and save changes. The TalkTalk Community Team OCE will then be able to link to your TalkTalk account(s).