European Patent Convention · Search and examination procedure
Rules 161 and 162 EPC: Amendment of the application; claims incurring fees
Annotated by Mahish Guru, Co-founder and CEO, PatentAssist.ai
Updated
Rule 161 EPC sets a six-month period, after a Euro-PCT application enters the European phase, to amend the application or reply to the international search opinion. Rule 162 charges claims fees in the same communication for every claim beyond 15.
Text of Rules 161 and 162 EPC
(2) Where the European Patent Office draws up a supplementary European search report on a Euro-PCT application, the application may be amended once within a period of six months from a communication informing the applicant accordingly. The application as amended shall serve as the basis for the supplementary European search.
(1) If the application documents on which the European grant procedure is to be based comprise more than fifteen claims, claims fees shall be paid for the sixteenth and each subsequent claim as laid down in the Rules relating to Fees within the period under Rule 159, paragraph 1.
In plain English
After a Euro-PCT application enters the European phase, the EPO sends a combined communication under Rules 161 and 162 with a six-month period to amend, reply and pay any outstanding claims fees.
Which paragraph applies depends on who searched. Under Rule 161(1), where the EPO was the International Searching Authority (or supplementary authority) and, if a demand was filed, the IPEA, there is no supplementary search. If the EPO's written opinion, IPER or supplementary search report raised objections, a reply is mandatory, and without one the application is deemed withdrawn. If it was positive, any reply is voluntary.
Under Rule 161(2), where another office searched, the EPO will draw up a supplementary European search. You may amend once in the six months, and the amended application is what gets searched. That makes this the moment to file the claims you actually want examined in Europe.
Claims fees under Rule 162 are due at 31 months for claims beyond 15, €290 each up to the 50th and €720 from the 51st. If not paid then, they can still be paid within the Rule 161 period; if you file amended claims in that period, the fees are calculated on the amended set and overpayments are refunded. Any claim whose fee is not paid is deemed abandoned (Rule 162(4)).
The six-month period also matters for unity. At its end, the examining division looks for inventions the EPO did not search in the international phase and, under Rule 164, invites further search fees for them. Amendments filed later have to stay within what has been searched (Rule 137(5)).
Deadlines and fees
| Step | Time limit | Basis |
|---|---|---|
| Reply, amend and pay outstanding claims fees | 6 months from the Rules 161 and 162 communication | Rules 161(1) or (2), 162(2) |
| Claims fees for claims beyond 15 | 31 months (Rule 159(1)), or later within the Rule 161 period | Rule 162(1) and (2); RFees item 15 |
| Further processing if a mandatory Rule 161(1) reply is missed | 2 months from the loss-of-rights communication | Article 121; Rule 135(1) |
Common objections
Negative written opinion from the EPO as ISA
Reply to every objection with amendments, arguments or both. Treat it as the equivalent of a reply under Rule 70a for a direct European application.
Claims filed on entry relate to a different invention
They will trigger a Rule 164(2) invitation if the EPO did not search them as ISA. Decide on the claim set before the period ends, as later switching is blocked.
Drafting and prosecution tips
- Use the full six months to file a claim set tailored to European practice: two-part form where suitable, one independent claim per category, reference signs and a basis for every change.
- Count claims before paying at 31 months; reducing the claims in the Rule 161 period can save fees.
Related provisions
- Article 153 EPC · The European Patent Office as designated Office or elected Office
- Rule 164 EPC · Unity of invention and further searches
- Rule 137 EPC · Amendment of the European patent application
- Rule 70a EPC · Response to the extended European search report
- Rule 43 EPC · Form and content of claims
In the Guidelines for Examination (2026)
PatentAssist guides
EPC excerpts are quoted from the European Patent Convention, 17th edition, as amended and published by the European Patent Office. Practice notes follow the Guidelines for Examination in the EPO (April 2026) and the Boards of Appeal decisions cited. Fees are those in force from 1 April 2026. This is general information, not legal advice: check the official text and confirm deadlines with a European patent attorney.