European Patent Office – The end of the 10 day rule

Mark Houghton - European patent attorney - Patent outsourcing Limited

[email protected]


Key Information - Communications dated from 1st November 2023 onwards from the EPO will no longer be able to utilise the 10-day grace period, in which a response 10 days later than indicated from a simple calculation of the due date was permissible. The change is not retrospective.

In more detail:

If you deal with the European patent office, either directly or indirectly, you will have come across the 10-day rule. This is the legal fiction that some communications, such as Examination Reports, but not all examination reports, are deemed to arrive 10 days after the date on the letter. This connects with a phrase often used in such communications, that the due date for response is, say, four months from the date of receipt of the communication. In other words, a communication with the date of 1st January, with four months to respond, would have until 10th April in which to respond. As you can imagine there are many variations on this, depending upon the specific communication and whether there are intervening official holidays et cetera.

As you will realise from the title of this article this legal fiction, as of 1st November 2023, ends. Put simply, you should assume that what you see is what you get in terms of due dates for response. So, in other words, assume that the response is indeed due after the number of months specified, i.e. on the same date of the corresponding month X months ahead. Obviously, there are nuances such as a communication dated 31 October 2024 with four months to respond and with only 29 days in February in 2024 and 1st March 2024 falling on a Saturday, then a response by 4th March 2024 might be the calculation. However, if you are not a European practitioner then your counterpart, whom you instruct, will obviously need time to process any instruction, so contact them (or myself) if you need guidance.

There are of course transitional provisions. For example, the change is not retrospective and only applies to communications dated from 1st November 2023. A postal communication dated 31st October 2023 will still be deemed to have been received ten days later, on 10th November 2023, and so may give a deadline which expires later than one triggered by the 1 November communication.

The abolition of the 10-day rule is accompanied by the option for Official Representatives at the EPO to receive communications electronically, thus bypassing the postal system, which was the basis for the legal fiction that it took 10 days for the post to arrive.

Summary - Many European practitioners always reported the unamended due date, without the 10-day adjustment, so if you have previously assumed that there was always additional time, then that assumption will soon no longer be valid.




[1] EUROPEAN PATENT OFFICE, 'Information from the EPO: Notice from the European Patent Office dated 6 March 2023 concerning amended Rules 126, 127 and 131 EPC,' Official Journal of the European Patent Office, vol. 2023, no. 3, p. A29, March 2023. [Online]. Available:

[2] "Pixabay, 'Clear Glass with Red Sand Grainer,' Uploaded on Jan. 30, 2016. [Online]. Available: [Accessed: Oct. 12, 2023]."

Our website uses Cookies to personalise content, provide social media features and to analyse our traffic whilst delivering the best possible experience to our users. If you'd like to find out more, please read our Cookies Policy.