Great question! Without valid credentials or an NPN/writing number, an application may not be completed. The nature of our relationship with healthcare.gov requires us to provide proof that you are an agent. Providing your NPN/writing number and FFM ID also provides verification that you are a certified agent, and that your client has given you permission to access/process their file.
Before you submit your first application, check with the manager of the organization to verify that the NPN/writing number on your listed issuers is correct. Managers may check this by going into "Settings" from the user menu on the top right, and looking at the user's contract and licensure settings. After you are sure that your details are correct, you are good to go!