The restitutio in integrum or re-establishment of rights under the European Patent Convention (EPC) is a means of redress available to an applicant or patent proprietor who has failed to meet a time limit in spite of exercising "all due care required by the circumstances".
If the request for restitutio in integrum is accepted, the applicant or patentee is re-established in its rights, as if the time limit had been duly met.
According to decision G 1/86 of the Enlarged Board of Appeal of the European Patent Office, other parties such as opponents are not barred from the restitutio in integrum by principle.
Article 122(1) EPC reads: "An applicant for or proprietor of a European patent who, in spite of all due care required by the circumstances having been taken, was unable to observe a time limit vis-à-vis the European Patent Office shall have his rights re-established upon request if the non-observance of this time limit has the direct consequence of causing the refusal of the European patent application or of a request, or the deeming of the application to have been withdrawn, or the revocation of the European patent, or the loss of any other right or means of redress.
"Therefore, one of the conditions for re-establishment of rights to be possible is that: In relation to the "all due care" criterion, "an isolated mistake in a normally satisfactory system is excusable.