Responding to a Rule 161/Rule 162 Communication

Responding to a Rule 161/Rule 162 Communication

After a PCT (Patent Cooperation Treaty) application enters the European regional phase, the applicant is given a period in which they may amend the application, particularly the claims, before the application is further considered by the European Patent Office (EPO). This means that it is not necessary to make amendments immediately upon European phase entry – not even to avoid the excess claims fees that the EPO charges for claims exceeding 15. The timeframe for amending the application is set by the EPO’s Rule 161/Rule 162 Communication.

Rule 161/Rule 162 Communication

The EPO issues this communication soon after the application enters the European phase, setting a 6-month deadline for submitting amendments, presenting arguments, and paying any outstanding excess claims fees. As we will explain, sometimes it is necessary to respond to this communication and sometimes it is not. This 6-month deadline cannot be extended. However, if the required action is not taken and the application is deemed withdrawn, further processing is available: The applicant may carry out the required act subject to payment of additional fees, within a 2-month period set accordingly by the EPO.

This article discusses key considerations and strategies for responding to the R161/R162 communication.

Rule 161 communication

There are three versions of the Rule 161 communication, Form 1266AA, 1266BB and 1266CC. Form 1226CC under Rule 161(2) EPC, states that ‘you may amend your application once within a non-extendable period of six months’.

The EPO may issue Form 1226BB under Rule 161(1) EPC, which states that ‘you may comment on the written opinion or on the explanations to the supplementary international search report within a non-extendable period of six months after notification of the present communication’.

In other circumstances, the EPO issues Form 1226AA under Rule 161(1) EPC, stating ‘you are invited to correct any deficiencies noted in the written opinion of the International Searching Authority… Should you not comply with or comment on this invitation within the time limit, the application will be deemed to be withdrawn’.

In the first two cases (Forms 1226CC and BB), a response is optional. In the last scenario (Form 1226AA), a response is mandatory.

Why the difference?

The subsequent procedure and so the type of communication—R161(1) or R161(2)—depends on whether the EPO conducted the search during the international phase. If the EPO has already searched the application in the international phase, then it is ready to begin examination. If another authority was the international searching authority, then the EPO will carry out a supplementary search and the applicant is being given a chance to amend their application before that search is carried out.

If the EPO was the ISA – Rule 161(1)

During the international phase, the EPO may have acted as the International Searching Authority (ISA) or the Supplementary International Searching Authority (SISA). Additionally, if a demand for international examination was filed, the EPO may have acted as the International Preliminary Examining Authority (IPEA).

If the EPO raised objections in the search or examination report, it will issue Form 1226AA under Rule 161(1), setting a 6-month deadline for the applicant to respond (a ‘mandatory response’). Failure to respond within this period will result in the application being deemed withdrawn.

However, if the EPO’s search opinion is entirely positive, if any objections raised have already been overcome (e.g. during international examination), or if a response to objections has already been submitted (e.g. upon European phase entry), the EPO will issue Form 1226BB under Rule 161(1). In this case, responding within the 6-month period is optional.

Once the 6-month period expires, provided all necessary actions have been taken, the application will proceed to examination. Any further amendments after the 6-month period require the examiner’s consent. Such amendments are generally admissible if they relate to searched subject matter and remain within the scope of the original PCT application. Even so, to avoid complications, it is advisable to get the application ready for the subsequent examination during the 6-month period set by R161(1).

If the EPO was not the ISA - Rule 161(2)

If the EPO did not act as ISA or SISA, for example if the ISA was the USPTO, the EPO will not have performed a search on the application. In this case, R161(2) applies, and the EPO will issue Form 1226CC to give the applicant an opportunity to amend the application, particularly the claims, before the EPO carries out a supplementary patentability search. In this case, a response is not mandatory, but the applicant may choose to submit one voluntarily. However, is it beneficial to provide voluntary arguments and/or amendments at this stage?

When responding to the R161(2) communication, voluntary amendments—especially claim amendments—are more important than voluntary arguments, for several key considerations.

Since the European examiner has not yet conducted the search, it is important for applicants to amend the claims to include all the subject matter they want the search report to cover. If there is a risk that the application may be considered as containing multiple inventions, the applicant should list the invention they want to be searched first. This is because the European examiner typically searches only the first invention mentioned in the claim set. Any unsearched subject matter cannot be relied upon during European prosecution, and divisional applications may be required to pursue the unsearched subject matter separately. Additionally, if the claim set exceeds 15 claims, this stage presents an opportunity to condense the claims to minimise or avoid excess claims fees.

There are also procedural reasons to defer substantive arguments until later in the process. After the 6-month period set under R161(2), the EPO first produces a supplementary European search report and then issues an R70(2)/R70a(2) communication, setting a further 6-month period for the applicant to indicate whether they wish to proceed, and to submit comments and/or amendments in light of the supplementary search. Provided the required actions are taken within this further 6-month period, the EPO then progresses the application to the examination stage.

Since this later 6-month period allows the applicant to tailor their arguments more specifically to address the objections raised in the supplementary European search report, it may be more logical to wait until then to submit patentability arguments rather than doing so voluntarily during the R161(2) period. It is also worth noting that after the further 6-month period under R70(2)/R70a(2), additional amendments are again subject to the EPO examiner’s discretion (i.e. a situation similar to the one upon expiry of the 6-month period under R161(1)).

In cases where the International Search Authority (ISA), other than the EPO, has identified highly relevant prior art, the applicants may consider submitting voluntary arguments to address the prior art, which may help preclude potential objections and clarify the invention for the EPO, thereby increasing the chances of receiving a favourable supplementary European search report. However, the applicants should weigh this approach against the early expenditure of time, effort and resources as well as the fact that EPO examiners work independently and may have distinct patentability views from the examiners of other offices. These factors make it difficult to predict the benefits of submitting voluntary arguments under Rule 161(2).

In general, many applicants use the 6-month period primarily to adapt the claims. This approach offers multiple advantages, including optimising claims for the European supplementary search and reducing excess claims fees. Strategic claim amendments serve as a practical and cost-effective response to the R161(2) communication.

Claims fees and Rule 162 communication

In response to an R161/R162 communication, applicants may amend any part of the application. However, if the application has not been searched by the EPO, as discussed above, the focus is often more on amending the claims than devising patentability arguments. It is noted that the EPO’s excess claims fees can significantly affect overall costs. As of February 2025, the EPO charges EUR 275 per claim for the 16th to the 50th claims and EUR 685 per claim for the 51st and subsequent claims.

If the claim set still contains more than 15 claims at the end of the 6-month period, Rule 162 EPC requires payment of excess claims fees by the same deadline. Claims beyond the 15th that are unpaid will be deemed abandoned.

Abandoned claims may be recovered by requesting further processing within a 2-month period set by the EPO. However, this involves substantial costs, as the further processing fee is 50% of the unpaid excess claims fees. In addition, the unpaid excess claims fees must be paid within the same 2-month period. If the abandoned claims’ features are described elsewhere in the application, they may be reintroduced during examination, provided they have been searched by the European examiner.

While remedies exist, they are costly and risky. To minimise expenses and complications, it is advisable to condense claims to reduce excess claims fees and promptly settle any outstanding fees within the 6-month period set by R161/R162.

Once the required action is taken, applicants may waive the remaining portion of the 6-month period under the R161/R162 communication. This waiver allows the application to proceed to the next stage without delay. Otherwise, the EPO will wait until the full 6-month period elapses before progressing the application.

Conclusions

The EPO’s R161/R162 communication provides a valuable opportunity for applicants to adapt claims, potentially reducing or avoiding excess claims fees. It also allows for the submission of patentability arguments—whether mandatory or voluntary—to clarify the invention for the examiner.

For those seeking to expedite the process, it is possible to waive the R161/R162 communication under certain conditions, shortening the timeline by approximately six months.

If you would like to explore the considerations for claim amendments under R161/R162, we have a separate article on navigating claim amendments effectively.

Author: Julia Li

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