After receiving the European search report and before receipt of the first communication from the Examining Division, the applicant may, of his own volition, amend the description, claims and drawings.

After receipt of the first communication from the examiner, the applicant may "of his own volition, amend once the description, claims and drawings" provided that the amendment is filed at the same time as his reply. After replying to the first communication 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 VI, 2.4 ). 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. Any subsequent request to withdraw an amendment is itself a request for further amendment; thus, if this subsequent request occurs after reply to the first communication from the examiner, the corresponding amendment will be admitted only if the examiner consents. In exercising his discretion under Rule 86(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.

In deleting subject-matter from an application, the applicant should avoid any statement which could be interpreted as abandonment of that subject-matter. Otherwise the subject-matter cannot be reinstated.