I have a player who filled out a new RPGA card but has lost the scratch off registration code to finish the registration process. 
I have already reported events using his number. How do we fix this? Thanks.
I would suggest that he contacts WotC using their customer service system - either by phone or using the 'Email Us' tab, and explains what happens.
They should be able to reset his password, although there may be a problem if they don't have an email address associated with the RPGA account - which they obviously won't! It may have to wait until you mail in the application and they add the data manually - but Customer Services should be able to advise.
Incidentally, if the Email Us tab doesn't work, see the thread linked from my signature.
Hope that helps!
I was afraid of that. I was hoping for an easier fix, such as just giving him another card and just reporting that number from now on, but I guess that might confuse things a bit for the people handling it on the other end. Thanks!
Ah, well that would work too.
You can even get customer service to merge the two numbers - and as there aren't rewards for playing RPGA events, just for GMing (and keeping contact details up to date), he wouldn't be losing anything by getting a second number.
He probably shouldn't have two numbers, but if he really wants to sign in for some reason - particularly if he wants to start organising events himself - getting him a new number would probably be best.