All notifications by postal services must be by registered letter (see also OJ EPO 2019, A57). The President of the EPO has, so far, not named any other documents to be notified by registered letter with advice of delivery or equivalent.[Rule 126; ]

The letter is deemed to be delivered to the addressee on the tenth day following its handover to the postal service provider, unless the letter has failed to reach the addressee or has reached him at a later date; in the event of any dispute, it is incumbent on the EPO to establish that the letter has reached its destination or to establish the date on which the letter was delivered to the addressee, as the case may be.

Notification is deemed to have been effected even if acceptance of the letter has been refused.

The law of the state on the territory of which the notification is made applies to other matters concerning notification, e.g. the question whether delivery to a person other than the addressee constitutes an effective notification to the latter.