Whereas some national laws such as the German Law know for a long time the opportunity to file protective letters, this opportunity does not exist in other jurisdictions of UPC countries such as Austria.

When it comes to the UPC, the opportunity to file protective letters will be given to anybody who considers it as likely that an application for provisional measures against him as a defendant may be lodged before the UPC in the near future. Protective letters are an important defence tool as they ensure that in case a request for a preliminary injunction is filed the court will have to consider the arguments as stated in the protective letter instead of deciding just ex parte.

However, protective letters should only be used if considerably good arguments can be presented therein. Otherwise they may have a counter-productive effect and make it even more likely that a preliminary injunction (“PI”) will be granted by the court (as the judges may think: if the defendant has no better arguments at hand, we should grant a PI).

Rule 207 of the Rules of Procedure state that a protective letter shall be filed with the Registry in the language of the patent. It shall (in the sense of: must) contain:

• the name of the defendant or defendants filing the protective letter and of the defendant’s representative;
• the name of the presumed applicant for provisional measures;
• postal and electronic addresses for service on the defendant filing the protective letter and the names of the persons authorised to accept service;
• postal and, where available, electronic addresses for service on the presumed applicant for provisional measures and the names of the persons authorised to accept service if known;
• where available, the number of the patent concerned and, where applicable, information about any prior or pending proceedings relating to the patent concerned before the Unified Patent Court including any action for revocation or a declaration of non-infringement pending before the central division and the date of any such action, the European Patent Office or any other court or authority;
• the statement that the letter is a Protective letter.

The Protective letter may (in the sense of: can) contain:

• an indication of the facts relied on, which may include a challenge to the facts expected to be relied on by the presumed applicant and/or, where applicable, any assertion that the patent is invalid and the grounds for such assertion;
• any available written evidence relied on;
• the arguments of law, including the reasons why any Application for provisional measures should be rejected.

In general, it may be wise to argue on both non-infringement and invalidity issues as both will be taken into consideration by the UPC in PI proceedings.

The costs for filing a protective letter are fairly low (€ 200). If no Application for provisional measures has been lodged within six months from the date of receipt of the protective letter, the protective letter shall be removed from the register unless the person who has lodged the protective letter has prior to the expiry of such period applied for an extension of six months and paid a fee for the extension; such extension fee is also very low (€ 100). Further extensions may be obtained on further payments of the extension fee.

Where an Application for provisional measures is lodged, the Registrar shall forward a copy of the protective letter to the applicant as soon as practicable. The protective letter shall not be publicly available on the register until it has been forwarded to the applicant.

This means that at the time of filing the PI request the PI applicant does not know whether there exists a protective letter. He learns to know, however, after having filed the application. The PI applicant has then the opportunity to decide to withdraw the PI request if he deems the arguments brought in the protective letter as so strong that he does not want to go forward in PI proceedings anymore. In such case, the protective letter will not become public, and the person/entity who has filed the protective letter will not be informed that a PI request was filed.

An interesting question will be how in praxis the judges will deal with the content provided in protective letters, and whether there will be differences in this regard between judges that have experiences with protective letters in their national jurisdictions and others that have not. Although such differences may indeed play a role at the beginning, it can be expected that after a while the approaches of the different divisions of the UPC will become more and more harmonized which will of course also be triggered by the future case law of the Court of Appeal.