The substantive requirement for registration of the unitary effect is that the European patent is granted with the same set of claims in respect of all participating member states. This means that all these countries must be designated in the European Patent. Withdrawal of designations or limitation of the claims with respect to any of the designated states would prevent an applicant from being able to obtain a European patent with unitary effect.Concerning the formal requirements, the request for unitary patent protection should be filed at the EPO no later than 1 month after the date on which the mention of the grant is published in the European Patent Bulletin. The request must be in writing in the language of the proceedings.
There is no official fee due for the request of a unitary patent.
Upon registration of the unitary effect, the unitary patent will have unitary character retroactively from the date of publication of mention of grant in the European Patent Bulletin, in all participating member states at the time of registration.