Novelty Grace Period Systems in Japan and the United States

Novelty Grace Period Systems in Japan and the United States

November 14, 2025
Akihiro Ryuka
Patent Attorney (Japan) / Attorney-at-Law (California)

1. Overview of Novelty Grace Period Systems

To be considered “novel,” an invention or design must not have been publicly disclosed before the filing date.
Public disclosures — such as conference presentations, trade show exhibitions, or online postings — made prior to filing can destroy novelty.
This applies even when the disclosure is made by the inventor or applicant themselves.

To provide relief in such situations, Japan and the U.S. have established “novelty grace period” systems.
If certain conditions are met, disclosures made by the applicant (or based on the applicant’s intent) will not be regarded as novelty-destroying, allowing the invention or design to remain eligible for patent or design registration.

2. Novelty Grace Period in Japan

(1) Requirements

To claim the novelty grace period in Japan, the following conditions must be met:

• The disclosure must have been made by a person having the right to obtain a patent or design registration.
• The applicant must be the person having such right (or their successor).
• The application must be filed within one year from the date of the disclosure.

For applications claiming priority under the Paris Convention, the Japanese filing must still occur within one year from the novelty-destroying disclosure date.

(2) Procedures

To apply the novelty grace period, the following procedures are required:

1. Statement at filing:
   The application must include an indication that the applicant seeks to apply the novelty grace period provisions.
2. Submission of evidentiary documents:
   Documents proving that the disclosure qualifies must be submitted within 30 days from the filing date.

For international applications, the timing differs:

Patents:

• Within 30 days from the date on which 30 months from the priority date have passed, or
• If examination is requested within 30 months from the priority date, within 30 days from the examination request date.

Designs:

• In principle, within 30 days from the date of international publication.

(3) Effect

If the submitted evidence is accepted, the prior disclosure will not be considered when assessing novelty or registrability.

(4) Notes for Design Applications

Special attention is required for design filings:

• The grace period applies not only to the same design but also to:
  • Similar designs
  • Designs easily creatable based on the disclosed design
• If the same design was disclosed multiple times, once the earliest disclosure is successfully covered by the grace period, later disclosures based on it will also not be considered in the novelty or registrability assessment.

3. Novelty Grace Period in the United States (Patents & Designs)

(1) Overview

The United States provides a “grace period” under which disclosures made by the inventor/applicant, or disclosures derived from them, do not destroy novelty if they occurred within one year before filing.
This applies to both utility patents and design patents.

(2) Requirements

To qualify for the U.S. grace period:

• The U.S. application must be filed within one year from the date of the disclosure.
  For PCT applications, the international filing date is used; for Paris Convention filings, the priority date applies.
• The disclosure must have been made by the inventor or by someone who obtained the information from the inventor.

(3) Procedures

In the United States, no special declaration or evidentiary submission is required at the time of filing.
The grace period applies automatically if the statutory conditions are met.