What happens if the requirement to appoint a professional representative is not observed?
In case of failure to appoint a professional representative where this is required, the applicant will be invited by the EPO to do so within a time limit of two months. Until the EPO is informed of a (valid) appointment, any procedural step taken by the applicant will be deemed not to have been taken. If within due time the deficiency has not been corrected, the application will be refused.
Source: http://www.epo.org/applying/international/guide-for-applicants/html/e/ga_c5_3_3.html
Date retrieved: 17 May 2021