If you have airline stock, you may register for eAWB without IATA or CASS. Airlines distribute stock to some forwarders which will have a specific account number that may be used for registration.
If you possess airline stock, call your local office and ask what ID or code needs to be mentioned on the FWB/FHLs that will be sent.
English 
Chinese (China) 
Chinese (Hong Kong) 
French 
German 
Italian 
Japanese 
Portuguese 
Romanian 
Slovak 
Spanish (Colombia) 
Spanish (Chile) 
Spanish (Ecuador) 
Spanish (Mexico) 