< Back to latest news & events

Knowledge Hub

Changes to the procedure for remedying patent applications at the EPO

October 2022

From 1 November 2022, the EPO has announced changes to the procedure for remedying patent applications that contain parts that have been included erroneously and updated the procedure for filing missing parts of a patent application.

At present time, the EPO only allows filing of missing parts of a patent application (e.g. drawings, sections of a description) under Rule 56 EPC, which the Legal Board of Appeal interprets narrowly. Under the current Rule 56 EPC, a patent application may retain its priority claim from an earlier patent application, if the filed missing parts of a patent application are:

  1. ‘Completely contained’ within the earlier patent application (which the patent application in question claims priority from); and
  2. Filed within two months of the date of filing of the patent application, or from the date of the relevant communication from the EPO.

If Rule 56 EPC is not complied with, the filing date of the patent application may be amended to the date that the missing parts of the patent application are filed. This re-dating penalty generally results in any potential priority claim that the patent application may have held, being pushed back, potentially affecting the patentability of a patent application.

In contrast, the EPO does not currently have any active procedure to remedy occurrences where parts of a patent application have been filed erroneously.

New Rule 56a EPC

Though undesirable, occasionally through human error, mistakes may occur during the filing of a patent application, resulting in parts of a patent application being included erroneously (e.g. drawings containing unwanted, confidential information) or containing errors (e.g. drawings with unintended visual issues). In order to remedy these mistakes when they do occur, a new EPC regulation, Rule 56a EPC, on correcting erroneous filings will enter into force on 1 November 2022.

Rule 56a EPC aligns the EPC with Rule 20.5bis PCT and allows the replacement of erroneously filed application documents (e.g. drawings, sections of the description) for patent applications filed on or after 1 November 2022. It will thus offer an equivalent to the PCT procedure, allowing the EPO, as the receiving office, to fully apply the PCT provision.

Similar to Rule 56 EPC, in order to claim priority from an earlier patent application and therefore avoid the aforementioned re-dating penalty, filed replacement parts must also be ‘completely contained’ within an earlier patent application, and filed within two months of either the date of filing the patent application or the date of the relevant communication from the EPO. In contrast to the current Rule 56 EPC, the patent application must, however, have claimed priority to the earlier patent application at the date that the patent application was filed.

Rule 56(3) EPC

As of 1 November 2022, Rule 56(3) EPC is to be updated to state that a priority claim to an earlier patent application must be made on the date that the patent application in question was filed, if it is used to file a missing part of a patent application. If a priority claim is added thereafter, under Rule 52(2) EPC, it cannot serve as a basis for filing a missing part of a patent application. As such, the applicability of Rule 56 EPC is to be restricted by this update.


This article was prepared by HGF Trainee Patent Attorney Theodore Jemmott.

Latest updates

The FoodTech Series #1 | Multi-parameter claims, examples outside the scope of the claims: when improvement occurs and evidence becomes easier to demonstrate

            The Boards of Appeal of the EPO (BoA) are the appeal body that reviews EPO decisions; in this case, they ruled on an opposition …

Read article

A New Era for AI Patents in the UK: Supreme Court Aligns with the EPO

The UK Supreme Court has handed down its long-awaited judgment in Emotional Perception AI Limited (EPAI) vs Comptroller General of Patents, a decision which serves to significantly change the way …

Read article
Event - 23rd - 25th March 2026

HGF are Gold Sponsors of IPBC Europe 2026

HGF are proud sponsors of IPBC Europe 2026, taking place from 23-25 March 2026 at the Pullman Paris Montparnasse. Bringing together patent pioneers, in-house leaders and private practice specialists, IPBC …

Event details
Event - 8th - 11th February 2026

AUTM Meeting 2026

We are attending the AUTM Annual Meeting from 8–11 February, a flagship event bringing together technology transfer professionals from across the globe. AUTM connects innovators, universities, and industry leaders to …

Event details

The Antibody Series #5 | Epitope-defined antibody claims: when “binds to this epitope” becomes a risk of insufficiency

The Boards of Appeal of the EPO (BoA) are the appeal body that reviews decisions made at the EPO; here, they reviewed an appeal in opposition proceedings after the revocation …

Read article

The Deity Shoes case: a question of design activity and the constraints on a designer’s freedom

The footwear brand Deity Shoes sought to enforce their Community Design rights, both registered and unregistered, against Mundorama Confort and Stay Design. However, Mundorama Confort and Stay Design found fault …

Read article

The Antibody Series #4 | pH points in antibody claims: when “same pH ” becomes an addition of matter

The Boards of Appeal of the EPO (BoA) are the appeal body that reviews EPO decisions; in this case, they reviewed a revocation in opposition of a patent relating to …

Read article

The Antibody Series #3 | Antibody code names in claims: why “ACZ885” is not sufficient to define the antibody

The Boards of Appeal of the EPO (BoA) are the appeal body that reviews EPO decisions. In this case, they examined a claim that identified an antibody by an internal …

Read article