The Electronic Filing System of the United States Patent and Trademark Office (USPTO), also referred to as EFS-Web or simply EFS, is a web-based system for submitting patent applications and related documents electronically.
All users may file new applications for accelerated examination, design patents, design patent reissues, international applications for filing in the US receiving office, provisional applications, reexamination requests, utility patents under 35 USC 111 (a), utility patent reissues, U.S. National Stage applications under 35 USC 371, ASCII text files (for sequence listings, computer listings, mega tables, mathematical formulae, chemical formulae, and 3D protein crystal structures), and petitions under 37 CFR 1.378(c). Applications must be in PDF format.
Users who have registered may also file follow-on documents and/or fees for previously filed applications, and pre-grant publications.
After filing via EFS, users are sent an electronic receipt that acknowledges the submission date. Submissions are available for viewing on Private PAIR within hours of submission.