I have an old 401 rollover which is from a different state. IB doesnot allow me to convert. :-( "The states of legal residence don't match"
I'd think you'd need to update your address with the 401k broker and then perform the conversion. Also try calling IB and see if they can maybe fix it over the phone.
I guess I misunderstood what you were saying ... I thought you meant you were trying to convert from a 401k (say at Fidelity) to IB. However in this thread of course you meant from an IRA at IB (rolled over from a 401k) to your Roth. I would call IB and ask them how to fix it. You may need to update the information on your rollover account (you may be able to do this online I'd think).
I can change account HOLDER address online, but there is no place to change account legal residence state.