The U.S. Patent & Trademark Office (USPTO) requires that non-provisional patent applications filed on or after June 30, 2023 be submitted electronically in Office Open XML “DOCX” file format in order to avoid a non-DOCX official surcharge. This means applications can still be filed electronically in PDF format, or by paper, but doing so will require payment of an additional official fee that varies according to the applicant’s entity size (initially $400/$160/$80 for large/small/micro entities).
What Types of Applications Must be in DOCX Format?
The DOCX filing requirement and non-DOCX surcharge currently applies only to the following U.S. patent applications:
- Utility patent applications (non-provisional) under 35 U.S.C. § 111(a)
- Includes direct U.S. filings with a Paris Convention foreign priority claim
- Includes PCT “bypass” applications
However, the non-DOCX surcharge currently does not apply to the following types of U.S. patent applications:
- Provisional patent applications
- Design patent applications
- Plant patent applications
- PCT national phase entries
Additionally, only certain portions of an application are covered by these requirements. In order to avoid the non-DOCX surcharge, the specification/description, claims, and abstract must all be in a compliant DOCX format. However, the drawings of an application do not need to be submitted in DOCX format. PDF format can be used for electronic submissions of figures without paying a non-DOCX surcharge.
The applicability of the non-DOCX surcharge to U.S. applications filed in a language other than English under 37 C.F.R. § 1.52(d)(1) is still rather unclear. The USPTO has not yet specified if a DOCX copy of (i) only the English translation, (ii) only the non-English original, or (iii) both the original and translation is required to avoid the surcharge. Though the USPTO’s justification for implementing the non-DOCX surcharge would seem to pertain only to the English translation.
Potential Problems
When application documents are electronically filed with the USPTO’s Patent Center system in DOCX format, they are “validated” to create a new DOCX file and also converted into another format (PDF) by the USPTO with a proprietary conversion/rendering engine prior to submission. For instance, tracked changes strikethrough and underlining/underscore formatting are automatically removed as part of file “validation”. However, that “validation” and conversion process can produce errors. Yet it is the “validated” DOCX file as modified by the USPTO’s system that is considered the “as filed” version that the USPTO actually relies upon for subsequent actions, and not the DOCX file as originally uploaded. The original applicant-created DOCX file is discarded by the USPTO as part of the “validation” process, meaning the USPTO does not preserve the original source file in unaltered (pre-validation) form. Underlying these concerns is the fact that DOCX format is not platform-stable, and rendering of a given document varies depending on the configuration of the computer that opens it. These aspects of DOCX filing are the major sources of concern.
Experience to date has shown that USPTO-side DOCX conversion error issues are particularly significant for application documents involving:
- Embedded mathematical equations created with a word processing program’s built-in equation editing functionality
- Embedded chemical formulas created with a word processing program’s built-in formula editing functionality
- Pseudo computer code with special indenting having technical meaning or special significance
- Data tables, particularly if the table introduces landscape page orientation that varies from other pages with portrait orientation or if there is complex table formatting with special formatting like substantively meaningful indenting within table cells
- Text in unusual characters/symbols or fonts, including Greek letters and/or uncommon accent marks with technical significance
- Claim autonumbering using automatic numbered list formatting
- Document creation using a word processing program other than a version of Microsoft Word® using a Latin-alphabet interface
- Document creation or editing with word processing program plug-ins or macros for machine translations, automatic application content population, and the like, especially when such plug-ins lock application formatting or content against further editing
Many of these things are fairly common in patent applications.
The USPTO treats a DOCX version as the definitive record copy, potentially allowing later correction of USPTO-side conversion errors by filing a petition and paying an accompanying official fee (which is even greater than the non-DOCX surcharge). However, the USPTO has clarified that only the “validated” DOCX file as modified by the USPTO’s systems during the filing process are treated as authoritative and not the applicant’s pre-“validation” source version. The USPTO has also said that petitions requesting a correction more than one year after a DOCX submission will not ordinarily be granted (except that, if applicable, incorporation by reference of a priority application or filing a pre-English-translation version may provide a different, independent basis to request correction more than a year later). This time limit stems from the USPTO saying it may discard applicant submissions after one year, retaining only a USPTO-converted/validated file. Although, even within that one-year time limit, USPTO alterations to the uploaded DOCX file to create a “validated” version might undermine reliance on the “original” for a correction due to alternations introduced by the “validation” process. Post-filing correction opportunities may therefore be limited.
The USPTO has permitted a highly limited opportunity to file a back-up applicant-generated PDF version (“Auxiliary PDF”) of an application filed in DOCX format that can further allow for later correction of USPTO-side conversion errors. However, this Auxiliary PDF submission is only permitted through June 30, 2023, during which time there are no extra official fees associated with an Auxiliary PDF or to petition to correct a USPTO-side conversion error based on such a PDF. After that date, the non-DOCX surcharge will apply as well as potential application size fees for any Auxiliary PDF submissions, in addition to any petition fees to correct USPTO-side errors.
The possibility of conversion errors arising at all and the burdens of timely requesting corrections have the potential to negatively impact applicants. Moreover, the increased applicant burden to format DOCX files and proofread converted files is potentially significant unto itself. In effect, DOCX filing saves some effort and expense for the USPTO by pushing or shifting certain burdens and risks onto applicants. The supposed benefits to applicants are trivial or meaningless.
Best Practices for DOCX Filing
The following are some suggested practices for DOCX filing. These are meant to supplement or clarify USPTO-provided guidance and frequently-asked-question (FAQ) responses that often serve more as disingenuous “gaslighting” to deny problems filers have encountered and conceal unstated, de facto requirements than to provide reliable, practical, actionable guidance. While a document might be modified shortly before filing to meet minimum requirements or best practices, there can be risks and potential problems associated with doing so, including the introduction of inadvertent errors and potential file corruption. It also may be significantly more time-consuming to later modify an application document for filing than to prepare it in a compliant way from the start.
Top DOCX application compliance tips:
- Use paragraph numbering (required), preferably paragraph autonumbering using at least four digits inside square brackets (“[0001]”)
- Omit line numbering
- Manual paragraph numbering is compliant but makes changes and amendments very burdensome
- Often the lack of paragraph numbering in an existing application document is the single most burdensome formatting change required for DOCX filing compliance
- Use a supported font, such as times new roman or arial (note that supported fonts are subject to change without notice)
- There have been reports that some fonts the USPTO has explicitly identified as being supported are not actually fully supported
- While a document-wide font change action can be performed, it may not alter font in embedded equations or formulas, inserted images with text or alphanumeric characters, headers and footers, and the like
- Manually number claims with plain text numbers and avoid automatic “list” formatting using word processing program functionality
- USPTO systems will sometimes modify claims in numbered list format to number each clause within a claim separately, disrupting intended claim numbering
- Use of auto-updating cross-reference fields to indicate claim dependencies sometimes leads to errors in conversion, such as converting all claim dependency references to a prior claim from various numbers to zero (0)
- Consider using an inserted image of a complex formula or equation rather than using one generated by a word processing program’s equation editor
- Inserted images must have sufficient resolution to be readable
- Provide figures in a separate document, rather than as pages of the same document containing the application text (specification)
- Deletion of pages containing drawings can sometimes produce unintended changes to the formatting of remaining pages in a DOCX file, such as deletion of page numbering, changes to margins, and the like
- Use an English version of the proprietary Microsoft Word® word processing program
- There are variants of the DOCX format and other nominally DOCX compatible word processing programs will not necessarily create files that will be processed the same way by the USPTO’s proprietary conversion engine
- Use of versions of the Microsoft Word® program intended for use with non-Latin chaccter alphabets may render differently on an English-language version of that program, such as removing inter-word spacing
- Avoid use of highly customized application templates with macros or uncommon/complex embedded formatting settings
- Simplify! In general, documents with simpler formatting are more likely to be compliant and less likely to result in conversion errors than more complexly formatted ones. Use complex, customized formatting only when strictly necessary or unavoidable
The USPTO provides DOCX-compliant utility patent application templates that could optionally be used. There is a basic template and another with essentially all possible application section headings identified. The basic template will like be more appropriate in most situations, with less extraneous section headings that are likely inapplicable. However, the use of automatic list claim numbering in these templates can still cause conversion errors and is not seen as actually compliant; thus, manual text-only claim numbering should be used in place of the list-style autonumbering in those templates.
While the USPTO asserts that DOCX file metadata is automatically removed from documents when filed, it is recommended to independently assess and remove any sensitive metadata before filing. Such metadata could relate to document revisions and the like. While such information is not necessarily harmful to an applicant’s interests, its presence in filed documents might possibly increase litigation discovery burdens if a resultant patent is ever enforced. In Microsoft Word, accessing the “File” > “Info” menu and utilizing the “Inspect Document” feature can help identify and then remove metadata. But be careful not to remove necessary document fields like page numbers appearing in footer margins.
One difficulty with identifying errors is that meaningful proofreading requires first uploading the DOCX file to the USPTO’s Patent Center and then reviewing a USPTO-converted file. While Patent Center provides some feedback about certain possible DOCX compatibility issues during the file upload and submission process, such automated feedback will never identify substantive content errors such as unintended changes to numerical values or technically meaningful formatting.
Non-DOCX Filing Alternatives
In some instances, electronically filing an application in PDF format and paying the non-DOCX surcharge may be more efficient than spending considerable time proofreading converted documents to check for errors. “Last minute”, urgent, or rush filings of applications with potentially problematic equations, formulas, data tables, text formatting, or the like may not allow sufficient time for proofreading, and may suggest PDF format filing and payment of the non-DOCX surcharge.
Additionally, if the USPTO’s Patent Center system is unavailable and paper (hard copy) filing via express mail is required to meet a filing deadline or bar date, payment of official non-DOCX and paper-filing surcharges might be necessary.

Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.