There are cases that the Applicant/Agent gets the access code before the application is registered in WIPO DAS.
TDA Offices (USPTO, EPO, KIPO, JPO, CNIPA, EUIPO) provide the DAS access code to the applicant directly to the user.
According to the DAS service regulations, the access code should be given to the user, after registration in DAS, but somehow in some cases, it can happen that the applicant receives the access code before the registration was done.
In rare instances, there are files that have not been registered , or somehow the request to registration did not reached WIPO DAS (due to network problems).