The European Patent Office (EPO) opposition procedure allows any person to challenge the validity of a European patent within nine months of its grant. Oppositions are a commercially astute method for revoking others' patents as an alternative or addition to court proceedings. However, the opposition procedure has historically taken up to three years after grant to reach a decision – even for 'straightforward' cases. Whilst a decision is pending, there is legal uncertainty for all parties.

On 1 July 2016, the EPO introduced a streamlined opposition procedure that simplifies the procedure so that opposition proceedings can be brought to a faster conclusion. The aim is that the Opposition Division will reach a decision within two years from grant. This is achieved by imposing reduced time limits on both the patent proprietor and the EPO.

Once an admissible opposition has been filed, the EPO invites the patent proprietor to respond with observations and any amendments to the patent. The streamlined procedure reduces the response time limit from six months to four months except in exceptional circumstances.

Typically, the opposition procedure concludes with oral proceedings at which all parties present final arguments and the opposition division give a decision. Under the new procedure, the Opposition Division will set a date for oral proceedings and issue a provisional opinion on the validity of the patent within a couple of months from receipt of the proprietor's response. Consistent with the current procedure, requests to change this date will only be granted in exceptional circumstances.

Whilst the streamlined opposition procedure is likely to be welcomed by parties of oppositions, it remains to be seen whether the reduction in time will have any effect on the quality of the provisional opinions and whether the new timescales are achievable by the EPO. The new procedure also effectively removes further opportunity for submissions and thus the opposition and the proprietor's response should be as detailed as possible.

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