Applications may also be filed by fax with the filing offices of the EPO or with the competent national authorities of those contracting states which so permit, namely – at present – Austria (AT), Bulgaria (BG), Czech Republic (CZ), Denmark (DK), Finland (FI), France (FR), Germany (DE), Greece (GR), Iceland (IS), Ireland (IE), Liechtenstein (LI), Luxembourg (LU), Monaco (MC), Norway (NO), Poland (PL), Portugal (PT), San Marino (SM), Slovakia (SK), Slovenia (SI), Spain (ES), Sweden (SE), Switzerland (CH) and United Kingdom (GB). For further details, see the latest version of the brochure "National Law relating to the EPC".

Where a document transmitted by fax is illegible or incomplete, the document is to be treated as not having been received to the extent that it is illegible or that the attempted transmission failed and the sender must be notified as soon as possible (see the Decision of the President of the EPO dated 20 February 2019, OJ EPO 2019, A18).

If a European patent application is filed by fax, a written confirmation is required only where the documents are of inferior quality. In this case, the EPO will invite the applicant to supply such documents within a period of two months (Rule 2(1)). If the applicant fails to comply with this invitation in due time, the European patent application will be refused. To prevent duplication of files, applicants are asked to indicate on the paper version of the application documents the application number or fax date and the name of the authority with which the documents were filed and to make it clear that these documents represent "confirmation of an application filed by fax".