Who can file documents using EFS-Web?

Both Registered and Unregistered users are able to file. The major difference is that Registered users (i.e., those holding a digital certificate or working under the direction of a digital certificate holder) are able to view documents on Private PAIR after they file, while Unregistered users cannot. In addition, Registered users are able to file documents and/or fees associated with previously filed patent applications, Pre-grant publications, and Petitions under 37 CFR 1.378(c).

USPTO FAQ - Questions and Answers (15AUG2007)