Filing a French provisional patent application at INPI

Since 1 July 2020, French law lets an applicant file a provisional patent application (demande provisoire de brevet) at the Institut National de la Propriété Industrielle. The mechanism was introduced by Décret n° 2019-1316 of 4 December 2019, one of the implementing texts of the loi PACTE, and it lives in Articles R612-3-1 and following of the Code de la propriété intellectuelle (CPI).

The idea is simple: you obtain a filing date — and therefore a priority date under the Paris Convention — on the strength of a technical description alone. Claims are optional, the abstract is optional, and INPI does not carry out a search or an examination while the application is provisional. Nothing is published.

What the provisional is not: it is not a patent, it will never become a patent by itself, and it does not give you any right to stop anyone. It is a dated deposit of technical content. Everything it will ever be worth depends on what you do within the following twelve months.

Under Article R612-2 CPI, a natural person domiciled in a member state of the European Union or the European Economic Area, and a legal person with its seat or an establishment in such a state, may deal with INPI directly, without appointing a representative. A French start-up, a SATT, a university and an individual inventor living in France therefore all qualify to file a provisional themselves.

Applicants outside the EU/EEA — a US biotech, a Swiss institute, a UK company since Brexit — must act through a representative admitted before INPI, in practice a conseil en propriété industrielle (CPI) or a lawyer. The same rule applies to the later regularisation of the provisional.

Representation being optional is not the same as review being useless. A provisional that is later found to be missing the one example that supports your broadest claim cannot be repaired; a review by counsel before the upload is cheap insurance. What the law does not require is that the counsel presses the button.

The filing fee for a patent application filed electronically at INPI is 26 €. Natural persons, small and medium-sized enterprises (fewer than 1,000 employees, less than 25 % owned by a larger company), non-profit research and teaching bodies, and micro-enterprises benefit from the reduced rate, 13 €. The provisional itself carries no additional fee.

The costs arrive later: the search-report fee and the claims fees are due at regularisation, when the provisional becomes a standard application, and the real budget lines are the PCT and the national phases that may follow. A provisional is an inexpensive way to buy twelve months of decision time; it is not an inexpensive patent.

Because nothing can be added later, the description of a provisional must be written as if it were the final specification. Three requirements govern what you will be able to claim from it.

First, sufficiency. Article L612-5 CPI, like Article 83 of the European Patent Convention, requires the invention to be disclosed in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. A concept without a workable route to it is not a disclosure.

Second, no added matter. When the provisional is regularised, and when a later application claims its priority, the subject-matter may not extend beyond the content of the application as filed (Article L612-6 CPI; Article 123(2) EPC at the EPO). Ranges, alternatives and combinations that are not literally or implicitly there are lost.

Third, 'same invention' priority. Under the Enlarged Board of Appeal's decision G 2/98, a later claim is only entitled to the provisional's date if the skilled person can derive its subject-matter directly and unambiguously from the provisional. A claim that is broader than what you disclosed keeps only the later date — and your own intervening publications become prior art against it.

• Field of the invention and the technical problem, stated in the terms a patent examiner uses.
• At least one detailed embodiment, with the actual parameters — concentrations, temperatures, sequences, dimensions.
• The alternatives you genuinely contemplate, listed, not implied: bioisosteres, solvents, ranges with their end points, sub-ranges.
• Data or a credible rationale for the technical effect you will rely on; after G 2/21, an effect must be at least encompassed and embodied by the application as filed.
• Draft claims, even if optional — they force you to check that the description supports every generalisation.

INPI grants a filing date on a description written in any language, but a French translation must follow within the period INPI sets, failing which the application is deemed withdrawn. If you write in English because your team does, plan the translation as part of the same sprint.

The upload is made on the INPI e-procedures portal (procedures.inpi.fr) with a personal or company account. PDF/A is the safe format; drawings must be legible in black and white. A sequence listing, when relevant, should already follow WIPO Standard ST.26 so that it can be reused as is for the PCT.

From the filing date of the provisional, two deadlines run in parallel. Within twelve months you must either regularise the provisional into a standard French application — filing the claims, the abstract and paying the search fee — or withdraw it. A provisional that is neither regularised nor withdrawn is deemed withdrawn.

Also within twelve months, under Article 4 of the Paris Convention, you may file a PCT application, a European application or foreign national applications that claim the priority of the provisional. This is the route most biotech and pharma applicants take: the French provisional locks the date, the PCT keeps every jurisdiction open until month 30 or 31.

Two further points are frequently missed. A provisional cannot itself claim an earlier priority, so it is always the first filing of its content. And restoration of a missed priority period exists (Rule 26bis.3 PCT; Article 122 EPC for European applications) but is granted on strict criteria — treat month twelve as a hard wall.

Research does not stop on filing day. A common and legitimate strategy is to file a new provisional at each significant result — new compound, new indication, new data — and to combine them, within twelve months of the first, in one PCT application claiming multiple priorities (Article 8 PCT, Article 88 EPC).

Each claim of the PCT then takes the date of the earliest provisional that fully discloses it, and partial priority under G 1/15 lets a single generic claim carry several dates. Keeping a written matrix of which provisional supports which claim is the single most useful document you can bring to the PCT drafting meeting.

Under Article L611-7 CPI, an invention made by an employee in the course of an inventive mission belongs to the employer, who owes the employee an additional remuneration; inventions made outside such a mission but with the employer's means may be claimed by the employer against a fair price. Public researchers are subject to the same regime through the Code de la recherche. Fix inventorship and ownership before the upload — a chain-of-title defect is far more expensive to cure than a drafting one.