Do I have to appoint a professional representative?
If you have either a residence or a place of business within the territory of an EPC contracting state you are not obliged to be represented by a professional representative (European patent attorney). If you do not have either a residence or a place of business within the territory of an EPC contracting ("non-resident"), you may file a European patent application but must appoint a professional representative and act through them afterwards. Fees may be paid by anybody.
Patent grant procedures are highly complex, so if you are not experienced in patent matters, we strongly recommend consulting a professional representative.
Representation may also be undertaken by any legal practitioner qualified in one of the EPC contracting states and having their place of business within that state, to the extent that they are entitled in that state to act as a professional representative in patent matters.
Further details can be found in the European Patent Guide, point 4.1.023 ff.