The Order for Recovery is sent by the enforcing authority, not TEC.
Advice if a postal PCN was never received thus indicating a possible mail problem, is, when the CC payment period has expired, to check regularly for the debt registration, and not just wait for the OfR to arrive in the mail. Reason for this is, if it turns up very late, you've lost the opportunity to submit an in-time declaration. So check every week to see if the CC amount has gone up by £10. This is the TEC registration fee, so tells you they have registered the debt. You can download the form from TEC then, fill it in, and submit it.