What is the application size fee and when does it apply?

The application size fee is an additional fee that applies to patent applications with specifications and drawings exceeding 100 sheets of paper. The MPEP states:

37 CFR 1.16(s) sets forth the application size fee for any application (including any reissue applications) filed under 35 U.S.C. 111, the specification and drawings of which exceed 100 sheets of paper. The calculation of the number of sheets excludes any “Sequence Listing”, computer readable form (CRF) of a “Sequence Listing”, or a “Computer Program Listing Appendix” filed in an American Standard Code for Information Interchange (ASCII) plain text file or any “Sequence Listing XML” filed in an eXtensible Markup Language (XML) file on a read-only optical disc or via the USPTO patent electronic filing system in compliance with the rules.

The fee applies for each additional 50 sheets or fraction thereof over 100 sheets. This fee must be paid within the time period set by the USPTO to avoid abandonment of the application.