Subsequent to the applicable event mentioned in H‑II, 2.2, the applicant may amend only if the examiner consents to the amendments proposed. Giving the Examining Division this discretion is intended to ensure that the examination procedure is brought to a conclusion in as few actions as possible (see C‑IV, 3). In exercising its discretion the Examining Division must consider all relevant factors; in particular, it must balance the applicant's interest in obtaining a patent which is legally valid and the EPO's interest in bringing the examination procedure to a close in an effective way (in accordance with the principles set out in G 7/93). Furthermore, the exercise of discretion under Rule 137(3) needs to be reasoned.
As an exception to Rule 137(3), paragraph (b) of Rule 164(2) provides for a right to amend the application in response to the results of any search under Rule 164(2). This means that the applicant may make amendments of his own volition once in response to the communication under Art. 94(3) to which the search results under Rule 164(2) are annexed (see also H‑II, 7.4.1).
If an amendment is admissible, subsequent proceedings are based on the description, claims and drawings as amended. Consent to an amendment does not necessarily imply that the application as amended is free from any objection under the EPC. Distinctions should be drawn between different types of amendments.
Amendments remedying a deficiency in response to the preceding communication must always be admitted, provided they do not give rise to some new deficiency. Amendments limiting a claim which is already considered allowable should normally be admitted. The same applies to amendments improving the clarity of the description or claims in a manner clearly desirable.
A further factor is the amount of alteration to the application documents involved. Extensive reworking of the description or claims may be a proper response to highly relevant further prior art of which the applicant has only just become aware (e.g. either through further citation by the examiner or through knowledge obtained from another source). Regarding less extensive amendments, the examiner should adopt a reasonable approach, trying to balance fairness to the applicant against the need to avoid unnecessary delay and excessive and unjustified additional work for the EPO. In exercising his discretion under Rule 137(3), the examiner should bear in mind the length of the proceedings to date and whether the applicant has already had sufficient opportunity for amendments. He should refuse in particular amendments reintroducing deficiencies previously pointed out to and removed by the applicant.
Additional reasons for not admitting amendments according to Rule 137(3) include the non-admittance of:
where this is for reasons of procedural economy (taking into account the applicant's right to comment according to Art. 113(1)), where Rule 137(4) is not complied with in respect of the request in question.