Doe one or both of the apportioned plates remain?
Both of the apportioned plates are remaining and I need to know what I should do with them when I receive my new apportioned plates.
If one or both of the apportioned plates remain, you must send in the apportioned plate and your old cab card within 30 days after you receive your new apportioned plates.  Failure to return your license plates can result in suspension of your IRB account.  The IRB will issue new apportioned plates that have a different number along with a new matching cab card.
Are you aware of International Registration, by the way? What happens if I'm in Albany?