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European Patent Convention · Application requirements

Rules 56 and 56a EPC: Missing parts and erroneously filed documents

Annotated by , Co-founder and CEO, PatentAssist.ai
Updated

Rule 56 EPC lets you file missing pages of the description or missing drawings after the filing date, and Rule 56a lets you replace documents filed by mistake. Both normally re-date the application, unless the late parts were already in the priority application.

Text of Rules 56 and 56a EPC

(2) If missing parts of the description or missing drawings are filed later than the date of filing, but within two months of the date of filing or, if a communication is issued under paragraph 1 or under Rule 56a, paragraph 1, within two months of that communication, the application shall be re-dated to the date on which the missing parts of the description or missing drawings were filed. The European Patent Office shall inform the applicant accordingly.

Rule 56(2) EPC, excerpt. Full official text on epo.org

(1) If the examination under Article 90, paragraph 1, reveals that the description, claims or drawings, or parts of those application documents, appear to have been erroneously filed, the European Patent Office shall invite the applicant to file the correct application documents or parts within two months. The applicant may not invoke the omission of such a communication.

Rule 56a(1) EPC, excerpt. Full official text on epo.org

In plain English

Rule 56 covers pages of the description or drawings that are missing from the application on filing. Rule 56a, in force since 1 November 2022, covers the case where the wrong documents were filed, for example the description of another case, and it also covers the claims.

The basic rule in both is the same. You can file the missing or correct parts within two months of the filing date, or within two months of an EPO invitation. The price is that the application is re-dated to the day the parts arrive. That can be fatal if the priority year has run out or if the invention has been published in the meantime.

Priority is the escape route. If the application claimed priority on its filing date and the missing or correct parts are completely contained in the priority application, you can keep the original date by asking for it within the same period, filing a copy of the priority application (unless the EPO already has it), any translation, and an indication of where the parts appear in it (Rule 56(3), Rule 56a(4)). Under Rule 56a, the wrongly filed documents then stay in the application alongside the correct ones; without the priority route, they are removed.

If you do nothing, references to missing drawings are deemed deleted. If you change your mind after re-dating, you can withdraw the late parts within one month of the EPO's notification and the original date is restored (Rule 56(6), Rule 56a(7)). If correct documents arrive after the search has started, a further search fee is due within one month (Rule 56a(8)).

None of these periods can be rescued by further processing (Rule 135(2)), and you cannot rely on the EPO having failed to send an invitation. Missing claims cannot be added under Rule 56.

Deadlines and fees

Step Time limit Basis
File missing parts or correct documents 2 months from the filing date, or from the EPO's invitation Rules 56(1) and (2), 56a(1) and (3)
Withdraw late-filed parts to undo re-dating 1 month from the EPO's notification Rules 56(6), 56a(7)
Further search fee if search already started 1 month from the invitation; search fee €1,595 Rule 56a(8); RFees item 2

Common objections

Re-dating

Check immediately whether the priority route is available and whether the new date is still within the priority year. If not, consider withdrawing the late parts and relying on the application without them.

Parts not completely contained in the priority application

Partial overlap is not enough. The EPO compares the late parts with the priority document as a whole, and any difference sends you back to re-dating.

Drafting and prosecution tips

  • Check the filing receipt and the page count of every document on the day of filing.
  • Always claim priority on the European filing itself when you can; it is what makes the date-saving route possible.
  • Keep the priority application and its translation ready to file within the two months.

Related provisions

In the Guidelines for Examination (2026)

PatentAssist guides

All annotated EPC provisions

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.